gencpp/project/gen.hpp

/*
	gencpp: An attempt at simple staged metaprogramming for c/c++.

	See Readme.md for more information from the project repository.

	Public Address:
	https://github.com/Ed94/gencpp
*/
#pragma once

#ifdef gen_time
#pragma region GENCPP DEPENDENCIES
//! If its desired to roll your own dependencies, define GENCPP_PROVIDE_DEPENDENCIES before including this file.
// Dependencies are derived from the c-zpl library: https://github.com/zpl-c/zpl
#ifndef GENCPP_ROLL_OWN_DEPENDENCIES

#if __clang__
#	pragma clang diagnostic ignored "-Wunused-const-variable"
#	pragma clang diagnostic ignored "-Wswitch"
#	pragma clang diagnostic ignored "-Wunused-variable"
#   pragma clang diagnostic ignored "-Wunknown-pragmas"
#	pragma clang diagnostic ignored "-Wvarargs"
#	pragma clang diagnostic ignored "-Wunused-function"
#endif

#if defined( GEN_HAS_ATTRIBUTE )
#	undef GEN_HAS_ATTRIBUTE
#endif
#if defined( __has_attribute )
#	define GEN_HAS_ATTRIBUTE( attribute ) __has_attribute( attribute )
#else
#	define GEN_HAS_ATTRIBUTE( attribute ) ( 0 )
#endif

/* Platform architecture */

#if defined( _WIN64 ) || defined( __x86_64__ ) || defined( _M_X64 ) || defined( __64BIT__ ) || defined( __powerpc64__ ) || defined( __ppc64__ ) || defined( __aarch64__ )
#	ifndef GEN_ARCH_64_BIT
#		define GEN_ARCH_64_BIT 1
#	endif
#else
#	ifndef GEN_ARCH_32_BIT
#		define GEN_ARCH_32_BIT 1
#	endif
#endif

/* Platform OS */

#if defined( _WIN32 ) || defined( _WIN64 )
#	ifndef GEN_SYSTEM_WINDOWS
#		define GEN_SYSTEM_WINDOWS 1
#	endif
#elif defined( __APPLE__ ) && defined( __MACH__ )
#	ifndef GEN_SYSTEM_OSX
#		define GEN_SYSTEM_OSX 1
#	endif
#	ifndef GEN_SYSTEM_MACOS
#		define GEN_SYSTEM_MACOS 1
#	endif
#	include <TargetConditionals.h>
#	if TARGET_IPHONE_SIMULATOR == 1 || TARGET_OS_IPHONE == 1
#		ifndef GEN_SYSTEM_IOS
#			define GEN_SYSTEM_IOS 1
#		endif
#	endif
#elif defined( __unix__ )
#	ifndef GEN_SYSTEM_UNIX
#		define GEN_SYSTEM_UNIX 1
#	endif
#	if defined( ANDROID ) || defined( __ANDROID__ )
#		ifndef GEN_SYSTEM_ANDROID
#			define GEN_SYSTEM_ANDROID 1
#		endif
#		ifndef GEN_SYSTEM_LINUX
#			define GEN_SYSTEM_LINUX 1
#		endif
#	elif defined( __linux__ )
#		ifndef GEN_SYSTEM_LINUX
#			define GEN_SYSTEM_LINUX 1
#		endif
#	elif defined( __FreeBSD__ ) || defined( __FreeBSD_kernel__ )
#		ifndef GEN_SYSTEM_FREEBSD
#			define GEN_SYSTEM_FREEBSD 1
#		endif
#	elif defined( __OpenBSD__ )
#		ifndef GEN_SYSTEM_OPENBSD
#			define GEN_SYSTEM_OPENBSD 1
#		endif
#	elif defined( __EMSCRIPTEN__ )
#		ifndef GEN_SYSTEM_EMSCRIPTEN
#			define GEN_SYSTEM_EMSCRIPTEN 1
#		endif
#	elif defined( __CYGWIN__ )
#		ifndef GEN_SYSTEM_CYGWIN
#			define GEN_SYSTEM_CYGWIN 1
#		endif
#	else
#		error This UNIX operating system is not supported
#	endif
#else
#	error This operating system is not supported
#endif

/* Platform compiler */

#if defined( _MSC_VER )
#	define GEN_COMPILER_MSVC 1
#elif defined( __GNUC__ )
#	define GEN_COMPILER_GCC 1
#elif defined( __clang__ )
#	define GEN_COMPILER_CLANG 1
#elif defined( __MINGW32__ )
#	define GEN_COMPILER_MINGW 1
#elif defined( __TINYC__ )
#	define GEN_COMPILER_TINYC 1
#else
#	error Unknown compiler
#endif

#ifndef GEN_DEF_INLINE
#	if defined( GEN_STATIC )
#		define GEN_DEF_INLINE
#		define GEN_IMPL_INLINE
#	else
#		define GEN_DEF_INLINE  static
#		define GEN_IMPL_INLINE static inline
#	endif
#endif

#if defined( GEN_ALWAYS_INLINE )
#	undef GEN_ALWAYS_INLINE
#endif

#ifdef GEN_COMPILER_MSVC
#	define forceinline __forceinline
#elif defined(GEN_COMPILER_GCC)
#	define forceinline inline __attribute__((__always_inline__))
#elif defined(GEN_COMPILER_CLANG)
#if __has_attribute(__always_inline__)
#	define forceinline inline __attribute__((__always_inline__))
#else
#	define forceinline inline
#endif
#else
#	define forceinline inline
#endif

#ifdef GEN_COMPILER_MSVC
#	define neverinline __declspec( noinline )
#elif defined(GEN_COMPILER_GCC)
#	define forceinline inline __attribute__( ( __noinline__ ) )
#elif defined(GEN_COMPILER_CLANG)
#if __has_attribute(__always_inline__)
#	define forceinline inline __attribute__( ( __noinline__ ) )
#else
#	define forceinline inline
#endif
#else
#	define forceinline inline
#endif

#ifndef count_of
#	define count_of( x ) ( ( size_of( x ) / size_of( 0 [ x ] ) ) / ( ( sw )( ! ( size_of( x ) % size_of( 0 [ x ] ) ) ) ) )
#endif

#ifndef is_between
#	define is_between( x, lower, upper ) ( ( ( lower ) <= ( x ) ) && ( ( x ) <= ( upper ) ) )
#endif

#ifndef min
#	define min( a, b ) ( ( a ) < ( b ) ? ( a ) : ( b ) )
#endif

#ifndef size_of
#	define size_of( x ) ( sw )( sizeof( x ) )
#endif

#ifndef swap
#	define swap( Type, a, b ) \
		do                     \
		{                      \
			Type tmp = ( a );  \
			( a )    = ( b );  \
			( b )    = tmp;    \
		} while ( 0 )
#endif

#ifndef zpl_cast
#	define zpl_cast( Type ) ( Type )
#endif

#ifndef global
#	define global static    // Global variables
#endif

#ifndef internal
#	define internal static    // Internal linkage
#endif

#ifndef local_persist
#	define local_persist static    // Local Persisting variables
#endif

#if defined(__GNUC__) || defined(__clang__)
	// Supports 0-10 arguments
	#define macro_num_args_impl( _0,                      \
		_1,  _2,  _3,  _4,  _5,  _6,  _7,  _8,  _9, _10,  \
		_11, _12, _13, _14, _15, _16, _17, _18, _19, _20, \
		N, ...                                            \
	) N
	// _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, \
	// _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, \
	// _41, _42, _43, _44, _45, _46, _47, _48, _49, _50,

	// ## deletes preceding comma if _VA_ARGS__ is empty (GCC, Clang)
	#define macro_num_args(...)                 \
 	macro_num_args_impl(_, ## __VA_ARGS__,      \
		20, 19, 18, 17, 16, 15, 14, 13, 12, 11, \
		10,  9,  8,  7,  6,  5,  4,  3,  2,  1, \
		0                                       \
	)
  	// 50, 49, 48, 47, 46, 45, 44, 43, 42, 41,              \
  	// 40, 39, 38, 37, 36, 35, 34, 33, 32, 31,              \
  	// 30, 29, 28, 27, 26, 25, 24, 23, 22, 21,
#else
	// Supports 1-10 arguments
  	#define macro_num_args_impl(                          \
  		 _1,  _2,  _3,  _4,  _5,  _6,  _7,  _8,  _9, _10, \
		_11, _12, _13, _14, _15, _16, _17, _18, _19, _20, \
 		 N, ...                                           \
	) N

	#define macro_num_args(...)                 \
	macro_num_args_impl( __VA_ARGS__,           \
		20, 19, 18, 17, 16, 15, 14, 13, 12, 11, \
		10,  9,  8,  7,  6,  5,  4,  3,  2,  1  \
	)
#endif

#define bit( Value_ )                             ( 1 << Value_ )
#define bitfield_is_equal( Type_, Field_, Mask_ ) ( (Type_(Mask_) & Type_(Field_)) == Type_(Mask_) )
#define ccast( Type_, Value_ )                    * const_cast< Type_* >( & (Value_) )
#define scast( Type_, Value_ )			          static_cast< Type_ >( Value_ )
#define rcast( Type_, Value_ )			          reinterpret_cast< Type_ >( Value_ )
#define pcast( Type_, Value_ )                    ( * (Type_*)( & (Value_) ) )
#define stringize_va( ... )                       #__VA_ARGS__
#define stringize( ... )                          stringize_va( __VA_ARGS__ )
#define do_once()      \
do                     \
{                      \
	static             \
	bool Done = false; \
	if ( Done )        \
		return;        \
	Done = true;       \
}                      \
while(0)

#define do_once_start  \
do                     \
{                      \
	static             \
	bool Done = false; \
	if ( Done )        \
		break;         \
	Done = true;

#define do_once_end    \
}                      \
while(0);

#pragma region Mandatory Includes
#	include <stdarg.h>
#	include <stddef.h>

#	if defined( GEN_SYSTEM_WINDOWS )
#		include <intrin.h>
#	endif
#pragma endregion Mandatory Includes

namespace gen
{
	constexpr
	char const* Msg_Invalid_Value = "INVALID VALUE PROVIDED";

	#pragma region Basic Types
	#ifndef GEN_U8_MIN
	#	define GEN_U8_MIN 0u
	#	define GEN_U8_MAX 0xffu
	#	define GEN_I8_MIN ( -0x7f - 1 )
	#	define GEN_I8_MAX 0x7f

	#	define GEN_U16_MIN 0u
	#	define GEN_U16_MAX 0xffffu
	#	define GEN_I16_MIN ( -0x7fff - 1 )
	#	define GEN_I16_MAX 0x7fff

	#	define GEN_U32_MIN 0u
	#	define GEN_U32_MAX 0xffffffffu
	#	define GEN_I32_MIN ( -0x7fffffff - 1 )
	#	define GEN_I32_MAX 0x7fffffff

	#	define GEN_U64_MIN 0ull
	#	define GEN_U64_MAX 0xffffffffffffffffull
	#	define GEN_I64_MIN ( -0x7fffffffffffffffll - 1 )
	#	define GEN_I64_MAX 0x7fffffffffffffffll

	#	if defined( GEN_ARCH_32_BIT )
	#		define GEN_USIZE_MIN GEN_U32_MIN
	#		define GEN_USIZE_MAX GEN_U32_MAX
	#		define GEN_ISIZE_MIN GEN_S32_MIN
	#		define GEN_ISIZE_MAX GEN_S32_MAX
	#	elif defined( GEN_ARCH_64_BIT )
	#		define GEN_USIZE_MIN GEN_U64_MIN
	#		define GEN_USIZE_MAX GEN_U64_MAX
	#		define GEN_ISIZE_MIN GEN_I64_MIN
	#		define GEN_ISIZE_MAX GEN_I64_MAX
	#	else
	#		error Unknown architecture size. This library only supports 32 bit and 64 bit architectures.
	#	endif

	#	define GEN_F32_MIN 1.17549435e-38f
	#	define GEN_F32_MAX 3.40282347e+38f

	#	define GEN_F64_MIN 2.2250738585072014e-308
	#	define GEN_F64_MAX 1.7976931348623157e+308
	#endif

	#if defined( GEN_COMPILER_MSVC )
	#	if _MSC_VER < 1300
	typedef unsigned char  u8;
	typedef signed char    s8;
	typedef unsigned short u16;
	typedef signed short   s16;
	typedef unsigned int   u32;
	typedef signed int     s32;
	#    else
	typedef unsigned __int8  u8;
	typedef signed __int8    s8;
	typedef unsigned __int16 u16;
	typedef signed __int16   s16;
	typedef unsigned __int32 u32;
	typedef signed __int32   s32;
	#    endif
	typedef unsigned __int64 u64;
	typedef signed __int64   s64;
	#else
	#	include <stdint.h>

	typedef uint8_t  u8;
	typedef int8_t   s8;
	typedef uint16_t u16;
	typedef int16_t  s16;
	typedef uint32_t u32;
	typedef int32_t  s32;
	typedef uint64_t u64;
	typedef int64_t  s64;
	#endif

	static_assert( sizeof( u8 ) == sizeof( s8 ), "sizeof(u8) != sizeof(s8)" );
	static_assert( sizeof( u16 ) == sizeof( s16 ), "sizeof(u16) != sizeof(s16)" );
	static_assert( sizeof( u32 ) == sizeof( s32 ), "sizeof(u32) != sizeof(s32)" );
	static_assert( sizeof( u64 ) == sizeof( s64 ), "sizeof(u64) != sizeof(s64)" );

	static_assert( sizeof( u8 ) == 1, "sizeof(u8) != 1" );
	static_assert( sizeof( u16 ) == 2, "sizeof(u16) != 2" );
	static_assert( sizeof( u32 ) == 4, "sizeof(u32) != 4" );
	static_assert( sizeof( u64 ) == 8, "sizeof(u64) != 8" );

	typedef size_t    uw;
	typedef ptrdiff_t sw;

	static_assert( sizeof( uw ) == sizeof( sw ), "sizeof(uw) != sizeof(sw)" );

	// NOTE: (u)zpl_intptr is only here for semantic reasons really as this library will only support 32/64 bit OSes.
	#if defined( _WIN64 )
	typedef signed __int64   sptr;
	typedef unsigned __int64 uptr;
	#elif defined( _WIN32 )
	// NOTE; To mark types changing their size, e.g. zpl_intptr
	#	ifndef _W64
	#		if ! defined( __midl ) && ( defined( _X86_ ) || defined( _M_IX86 ) ) && _MSC_VER >= 1300
	#			define _W64 __w64
	#		else
	#			define _W64
	#		endif
	#	endif
	typedef _W64 signed int   sptr;
	typedef _W64 unsigned int uptr;
	#else
	typedef uintptr_t uptr;
	typedef intptr_t  sptr;
	#endif

	static_assert( sizeof( uptr ) == sizeof( sptr ), "sizeof(uptr) != sizeof(sptr)" );

	typedef float  f32;
	typedef double f64;

	static_assert( sizeof( f32 ) == 4, "sizeof(f32) != 4" );
	static_assert( sizeof( f64 ) == 8, "sizeof(f64) != 8" );

	typedef s8  b8;
	typedef s16 b16;
	typedef s32 b32;
	#pragma endregion Basic Types

	#pragma region Debug
	#ifndef GEN_DEBUG_TRAP
	#	if defined( _MSC_VER )
	#		if _MSC_VER < 1300
	#			define GEN_DEBUG_TRAP() __asm int 3 /* Trap to debugger! */
	#		else
	#			define GEN_DEBUG_TRAP() __debugbreak()
	#		endif
	#	elif defined( GEN_COMPILER_TINYC )
	#		define GEN_DEBUG_TRAP() process_exit( 1 )
	#	else
	#		define GEN_DEBUG_TRAP() __builtin_trap()
	#	endif
	#endif

	#ifndef GEN_ASSERT
	#	define GEN_ASSERT( cond ) GEN_ASSERT_MSG( cond, NULL )
	#endif

	#ifndef GEN_ASSERT_MSG
	#	define GEN_ASSERT_MSG( cond, msg, ... )                                                      \
			do                                                                                       \
			{                                                                                        \
				if ( ! ( cond ) )                                                                    \
				{                                                                                    \
					assert_handler( #cond, __FILE__, zpl_cast( s64 ) __LINE__, msg, ##__VA_ARGS__ ); \
					GEN_DEBUG_TRAP();                                                                \
				}                                                                                    \
			} while ( 0 )
	#endif

	#ifndef GEN_ASSERT_NOT_NULL
	#	define GEN_ASSERT_NOT_NULL( ptr ) GEN_ASSERT_MSG( ( ptr ) != NULL, #ptr " must not be NULL" )
	#endif

	// NOTE: Things that shouldn't happen with a message!
	#ifndef GEN_PANIC
	#	define GEN_PANIC( msg, ... ) GEN_ASSERT_MSG( 0, msg, ##__VA_ARGS__ )
	#endif

	void assert_handler( char const* condition, char const* file, s32 line, char const* msg, ... );
	s32  assert_crash( char const* condition );
	void process_exit( u32 code );
	#pragma endregion Debug

	#pragma region Memory
	#ifndef kilobytes
	#	define kilobytes( x ) ( ( x ) * ( s64 )( 1024 ) )
	#	define megabytes( x ) ( kilobytes( x ) * ( s64 )( 1024 ) )
	#	define gigabytes( x ) ( megabytes( x ) * ( s64 )( 1024 ) )
	#	define terabytes( x ) ( gigabytes( x ) * ( s64 )( 1024 ) )
	#endif

	#define GEN__ONES          ( zpl_cast( uw ) - 1 / GEN_U8_MAX )
	#define GEN__HIGHS         ( GEN__ONES * ( GEN_U8_MAX / 2 + 1 ) )
	#define GEN__HAS_ZERO( x ) ( ( ( x )-GEN__ONES ) & ~( x )&GEN__HIGHS )

	//! Checks if value is power of 2.
	GEN_DEF_INLINE b32 is_power_of_two( sw x );

	//! Aligns address to specified alignment.
	GEN_DEF_INLINE void* align_forward( void* ptr, sw alignment );

	//! Aligns value to a specified alignment.
	GEN_DEF_INLINE s64 align_forward_i64( s64 value, sw alignment );

	//! Moves pointer forward by bytes.
	GEN_DEF_INLINE void* pointer_add( void* ptr, sw bytes );

	//! Copy non-overlapping memory from source to destination.
	void* mem_copy( void* dest, void const* source, sw size );

	//! Search for a constant value within the size limit at memory location.
	void const* mem_find( void const* data, u8 byte_value, sw size );

	//! Copy memory from source to destination.
	GEN_DEF_INLINE void* mem_move( void* dest, void const* source, sw size );

	//! Set constant value at memory location with specified size.
	GEN_DEF_INLINE void* mem_set( void* data, u8 byte_value, sw size );

	//! @param ptr Memory location to clear up.
	//! @param size The size to clear up with.
	GEN_DEF_INLINE void zero_size( void* ptr, sw size );

	#ifndef zero_item
	//! Clears up an item.
	#	define zero_item( t ) zero_size( ( t ), size_of( *( t ) ) )    // NOTE: Pass pointer of struct

	//! Clears up an array.
	#	define zero_array( a, count ) zero_size( ( a ), size_of( *( a ) ) * count )
	#endif

	enum AllocType : u8
	{
		EAllocation_ALLOC,
		EAllocation_FREE,
		EAllocation_FREE_ALL,
		EAllocation_RESIZE,
	};

	using AllocatorProc = void* ( void* allocator_data, AllocType type
		, sw size, sw alignment
		, void* old_memory, sw old_size
		, u64 flags );

	struct AllocatorInfo
	{
		AllocatorProc* Proc;
		void*          Data;
	};

	enum AllocFlag
	{
		ALLOCATOR_FLAG_CLEAR_TO_ZERO = bit( 0 ),
	};

	#ifndef GEN_DEFAULT_MEMORY_ALIGNMENT
	#	define GEN_DEFAULT_MEMORY_ALIGNMENT ( 2 * size_of( void* ) )
	#endif

	#ifndef GEN_DEFAULT_ALLOCATOR_FLAGS
	#	define GEN_DEFAULT_ALLOCATOR_FLAGS ( ALLOCATOR_FLAG_CLEAR_TO_ZERO )
	#endif

	//! Allocate memory with default alignment.
	GEN_DEF_INLINE void* alloc( AllocatorInfo a, sw size );

	//! Allocate memory with specified alignment.
	GEN_DEF_INLINE void* alloc_align( AllocatorInfo a, sw size, sw alignment );

	//! Free allocated memory.
	GEN_DEF_INLINE void free( AllocatorInfo a, void* ptr );

	//! Free all memory allocated by an allocator.
	GEN_DEF_INLINE void free_all( AllocatorInfo a );

	//! Resize an allocated memory.
	GEN_DEF_INLINE void* resize( AllocatorInfo a, void* ptr, sw old_size, sw new_size );

	//! Resize an allocated memory with specified alignment.
	GEN_DEF_INLINE void* resize_align( AllocatorInfo a, void* ptr, sw old_size, sw new_size, sw alignment );

	#ifndef alloc_item
	//! Allocate memory for an item.
	#	define alloc_item( allocator_, Type ) ( Type* )alloc( allocator_, size_of( Type ) )

	//! Allocate memory for an array of items.
	#	define alloc_array( allocator_, Type, count ) ( Type* )alloc( allocator_, size_of( Type ) * ( count ) )
	#endif

	/* heap memory analysis tools */
	/* define GEN_HEAP_ANALYSIS to enable this feature */
	/* call zpl_heap_stats_init at the beginning of the entry point */
	/* you can call zpl_heap_stats_check near the end of the execution to validate any possible leaks */
	void heap_stats_init( void );
	sw   heap_stats_used_memory( void );
	sw   heap_stats_alloc_count( void );
	void heap_stats_check( void );

	//! Allocate/Resize memory using default options.

	//! Use this if you don't need a "fancy" resize allocation
	GEN_DEF_INLINE void* default_resize_align( AllocatorInfo a, void* ptr, sw old_size, sw new_size, sw alignment );

	void* heap_allocator_proc( void* allocator_data, AllocType type, sw size, sw alignment, void* old_memory, sw old_size, u64 flags );

	//! The heap allocator backed by operating system's memory manager.
	constexpr AllocatorInfo heap( void ) { return { heap_allocator_proc, nullptr }; }

	#ifndef malloc
	//! Helper to allocate memory using heap allocator.
	#	define malloc( sz ) alloc( heap(), sz )

	//! Helper to free memory allocated by heap allocator.
	#	define mfree( ptr ) free( heap(), ptr )
	#endif

	GEN_IMPL_INLINE b32 is_power_of_two( sw x )
	{
		if ( x <= 0 )
			return false;
		return ! ( x & ( x - 1 ) );
	}

	GEN_IMPL_INLINE void* align_forward( void* ptr, sw alignment )
	{
		uptr p;

		GEN_ASSERT( is_power_of_two( alignment ) );

		p = zpl_cast( uptr ) ptr;
		return zpl_cast( void* )( ( p + ( alignment - 1 ) ) & ~( alignment - 1 ) );
	}

	GEN_IMPL_INLINE s64 align_forward_i64( s64 value, sw alignment )
	{
		return value + ( alignment - value % alignment ) % alignment;
	}

	GEN_IMPL_INLINE void* pointer_add( void* ptr, sw bytes )
	{
		return zpl_cast( void* )( zpl_cast( u8* ) ptr + bytes );
	}

	GEN_IMPL_INLINE void* mem_move( void* dest, void const* source, sw n )
	{
		if ( dest == NULL )
		{
			return NULL;
		}

		u8*       d = zpl_cast( u8* ) dest;
		u8 const* s = zpl_cast( u8 const* ) source;

		if ( d == s )
			return d;
		if ( s + n <= d || d + n <= s )    // NOTE: Non-overlapping
			return mem_copy( d, s, n );

		if ( d < s )
		{
			if ( zpl_cast( uptr ) s % size_of( sw ) == zpl_cast( uptr ) d % size_of( sw ) )
			{
				while ( zpl_cast( uptr ) d % size_of( sw ) )
				{
					if ( ! n-- )
						return dest;
					*d++ = *s++;
				}
				while ( n >= size_of( sw ) )
				{
					*zpl_cast( sw* ) d  = *zpl_cast( sw* ) s;
					n                  -= size_of( sw );
					d                  += size_of( sw );
					s                  += size_of( sw );
				}
			}
			for ( ; n; n-- )
				*d++ = *s++;
		}
		else
		{
			if ( ( zpl_cast( uptr ) s % size_of( sw ) ) == ( zpl_cast( uptr ) d % size_of( sw ) ) )
			{
				while ( zpl_cast( uptr )( d + n ) % size_of( sw ) )
				{
					if ( ! n-- )
						return dest;
					d[ n ] = s[ n ];
				}
				while ( n >= size_of( sw ) )
				{
					n                         -= size_of( sw );
					*zpl_cast( sw* )( d + n )  = *zpl_cast( sw* )( s + n );
				}
			}
			while ( n )
				n--, d[ n ] = s[ n ];
		}

		return dest;
	}

	GEN_IMPL_INLINE void* mem_set( void* dest, u8 c, sw n )
	{
		if ( dest == NULL )
		{
			return NULL;
		}

		u8* s = zpl_cast( u8* ) dest;
		sw  k;
		u32 c32 = ( ( u32 )-1 ) / 255 * c;

		if ( n == 0 )
			return dest;
		s[ 0 ] = s[ n - 1 ] = c;
		if ( n < 3 )
			return dest;
		s[ 1 ] = s[ n - 2 ] = c;
		s[ 2 ] = s[ n - 3 ] = c;
		if ( n < 7 )
			return dest;
		s[ 3 ] = s[ n - 4 ] = c;
		if ( n < 9 )
			return dest;

		k  = -zpl_cast( sptr ) s & 3;
		s += k;
		n -= k;
		n &= -4;

		*zpl_cast( u32* )( s + 0 )     = c32;
		*zpl_cast( u32* )( s + n - 4 ) = c32;
		if ( n < 9 )
			return dest;
		*zpl_cast( u32* )( s + 4 )      = c32;
		*zpl_cast( u32* )( s + 8 )      = c32;
		*zpl_cast( u32* )( s + n - 12 ) = c32;
		*zpl_cast( u32* )( s + n - 8 )  = c32;
		if ( n < 25 )
			return dest;
		*zpl_cast( u32* )( s + 12 )     = c32;
		*zpl_cast( u32* )( s + 16 )     = c32;
		*zpl_cast( u32* )( s + 20 )     = c32;
		*zpl_cast( u32* )( s + 24 )     = c32;
		*zpl_cast( u32* )( s + n - 28 ) = c32;
		*zpl_cast( u32* )( s + n - 24 ) = c32;
		*zpl_cast( u32* )( s + n - 20 ) = c32;
		*zpl_cast( u32* )( s + n - 16 ) = c32;

		k  = 24 + ( zpl_cast( uptr ) s & 4 );
		s += k;
		n -= k;

		{
			u64 c64 = ( zpl_cast( u64 ) c32 << 32 ) | c32;
			while ( n > 31 )
			{
				*zpl_cast( u64* )( s + 0 )  = c64;
				*zpl_cast( u64* )( s + 8 )  = c64;
				*zpl_cast( u64* )( s + 16 ) = c64;
				*zpl_cast( u64* )( s + 24 ) = c64;

				n -= 32;
				s += 32;
			}
		}

		return dest;
	}

	GEN_IMPL_INLINE void* alloc_align( AllocatorInfo a, sw size, sw alignment )
	{
		return a.Proc( a.Data, EAllocation_ALLOC, size, alignment, nullptr, 0, GEN_DEFAULT_ALLOCATOR_FLAGS );
	}

	GEN_IMPL_INLINE void* alloc( AllocatorInfo a, sw size )
	{
		return alloc_align( a, size, GEN_DEFAULT_MEMORY_ALIGNMENT );
	}

	GEN_IMPL_INLINE void free( AllocatorInfo a, void* ptr )
	{
		if ( ptr != nullptr )
			a.Proc( a.Data, EAllocation_FREE, 0, 0, ptr, 0, GEN_DEFAULT_ALLOCATOR_FLAGS );
	}

	GEN_IMPL_INLINE void free_all( AllocatorInfo a )
	{
		a.Proc( a.Data, EAllocation_FREE_ALL, 0, 0, nullptr, 0, GEN_DEFAULT_ALLOCATOR_FLAGS );
	}

	GEN_IMPL_INLINE void* resize( AllocatorInfo a, void* ptr, sw old_size, sw new_size )
	{
		return resize_align( a, ptr, old_size, new_size, GEN_DEFAULT_MEMORY_ALIGNMENT );
	}

	GEN_IMPL_INLINE void* resize_align( AllocatorInfo a, void* ptr, sw old_size, sw new_size, sw alignment )
	{
		return a.Proc( a.Data, EAllocation_RESIZE, new_size, alignment, ptr, old_size, GEN_DEFAULT_ALLOCATOR_FLAGS );
	}

	GEN_IMPL_INLINE void* default_resize_align( AllocatorInfo a, void* old_memory, sw old_size, sw new_size, sw alignment )
	{
		if ( ! old_memory )
			return alloc_align( a, new_size, alignment );

		if ( new_size == 0 )
		{
			free( a, old_memory );
			return nullptr;
		}

		if ( new_size < old_size )
			new_size = old_size;

		if ( old_size == new_size )
		{
			return old_memory;
		}
		else
		{
			void* new_memory = alloc_align( a, new_size, alignment );
			if ( ! new_memory )
				return nullptr;
			mem_move( new_memory, old_memory, min( new_size, old_size ) );
			free( a, old_memory );
			return new_memory;
		}
	}

	GEN_IMPL_INLINE void zero_size( void* ptr, sw size )
	{
		mem_set( ptr, 0, size );
	}

	struct Arena
	{
		static
		void* allocator_proc( void* allocator_data, AllocType type, sw size, sw alignment, void* old_memory, sw old_size, u64 flags );

		static
		Arena init_from_memory( void* start, sw size )
		{
			return
			{
				{ nullptr, nullptr },
				start,
				size,
				0,
				0
			};
		}

		static
		Arena init_from_allocator( AllocatorInfo backing, sw size )
		{
			Arena result =
			{
				backing,
				alloc( backing, size),
				size,
				0,
				0
			};
			return result;
		}

		static
		Arena init_sub( Arena& parent, sw size )
		{
			return init_from_allocator( parent.Backing, size );
		}

		sw alignment_of( sw alignment )
		{
			sw alignment_offset, result_pointer, mask;
			GEN_ASSERT( is_power_of_two( alignment ) );

			alignment_offset = 0;
			result_pointer   = (sw) PhysicalStart + TotalUsed;
			mask             = alignment - 1;

			if ( result_pointer & mask )
				alignment_offset = alignment - ( result_pointer & mask );

			return alignment_offset;
		}

		void check()
		{
			GEN_ASSERT( TempCount == 0 );
		}

		void free()
		{
			if ( Backing.Proc )
			{
				gen::free( Backing, PhysicalStart );
				PhysicalStart = nullptr;
			}
		}

		sw size_remaining( sw alignment )
		{
			sw result = TotalSize - ( TotalUsed + alignment_of( alignment ) );
			return result;
		}

		AllocatorInfo Backing;
		void*         PhysicalStart;
		sw            TotalSize;
		sw            TotalUsed;
		sw            TempCount;

		operator AllocatorInfo()
		{
			return { allocator_proc, this };
		}
	};

	struct Pool
	{
		static
		void* allocator_proc( void* allocator_data, AllocType type, sw size, sw alignment, void* old_memory, sw old_size, u64 flags );

		static
		Pool init( AllocatorInfo backing, sw num_blocks, sw block_size )
		{
			return init_align( backing, num_blocks, block_size, GEN_DEFAULT_MEMORY_ALIGNMENT );
		}

		static
		Pool init_align( AllocatorInfo backing, sw num_blocks, sw block_size, sw block_align );

		void free()
		{
			if ( Backing.Proc )
			{
				gen::free( Backing, PhysicalStart );
			}
		}

		AllocatorInfo Backing;
		void*         PhysicalStart;
		void*         FreeList;
		sw            BlockSize;
		sw            BlockAlign;
		sw            TotalSize;
		sw            NumBlocks;

		operator AllocatorInfo()
		{
			return { allocator_proc, this };
		}
	};
	#pragma endregion Memory

	#pragma region String Ops
	GEN_DEF_INLINE const char* char_first_occurence( const char* str, char c );

	GEN_DEF_INLINE b32   char_is_alpha( char c );
	GEN_DEF_INLINE b32   char_is_alphanumeric( char c );
	GEN_DEF_INLINE b32   char_is_digit( char c );
	GEN_DEF_INLINE b32   char_is_hex_digit( char c );
	GEN_DEF_INLINE b32   char_is_space( char c );
	GEN_DEF_INLINE char  char_to_lower( char c );
	GEN_DEF_INLINE char  char_to_upper( char c );

	GEN_DEF_INLINE s32  digit_to_int( char c );
	GEN_DEF_INLINE s32  hex_digit_to_int( char c );

	GEN_DEF_INLINE s32   str_compare( const char* s1, const char* s2 );
	GEN_DEF_INLINE s32   str_compare( const char* s1, const char* s2, sw len );
	GEN_DEF_INLINE char* str_copy( char* dest, const char* source, sw len );
	GEN_DEF_INLINE sw    str_copy_nulpad( char* dest, const char* source, sw len );
	GEN_DEF_INLINE sw    str_len( const char* str );
	GEN_DEF_INLINE sw    str_len( const char* str, sw max_len );
	GEN_DEF_INLINE char* str_reverse( char* str );    // NOTE: ASCII only

	// NOTE: ASCII only
	GEN_DEF_INLINE void str_to_lower( char* str );
	GEN_DEF_INLINE void str_to_upper( char* str );

	s64  str_to_i64( const char* str, char** end_ptr, s32 base );    // TODO : Support more than just decimal and hexadecimal
	void i64_to_str( s64 value, char* string, s32 base );
	void u64_to_str( u64 value, char* string, s32 base );

	GEN_IMPL_INLINE const char* char_first_occurence( const char* s, char c )
	{
		char ch = c;
		for ( ; *s != ch; s++ )
		{
			if ( *s == '\0' )
				return NULL;
		}
		return s;
	}

	GEN_IMPL_INLINE b32 char_is_alpha( char c )
	{
		if ( ( c >= 'A' && c <= 'Z' ) || ( c >= 'a' && c <= 'z' ) )
			return true;
		return false;
	}

	GEN_IMPL_INLINE b32 char_is_alphanumeric( char c )
	{
		return char_is_alpha( c ) || char_is_digit( c );
	}

	GEN_IMPL_INLINE b32 char_is_digit( char c )
	{
		if ( c >= '0' && c <= '9' )
			return true;
		return false;
	}

	GEN_IMPL_INLINE b32 char_is_hex_digit( char c )
	{
		if ( char_is_digit( c ) || ( c >= 'a' && c <= 'f' ) || ( c >= 'A' && c <= 'F' ) )
			return true;
		return false;
	}

	GEN_IMPL_INLINE b32 char_is_space( char c )
	{
		if ( c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' || c == '\v' )
			return true;
		return false;
	}

	GEN_IMPL_INLINE char char_to_lower( char c )
	{
		if ( c >= 'A' && c <= 'Z' )
			return 'a' + ( c - 'A' );
		return c;
	}

	GEN_IMPL_INLINE char char_to_upper( char c )
	{
		if ( c >= 'a' && c <= 'z' )
			return 'A' + ( c - 'a' );
		return c;
	}

	GEN_IMPL_INLINE s32 digit_to_int( char c )
	{
		return char_is_digit( c ) ? c - '0' : c - 'W';
	}

	GEN_IMPL_INLINE s32 hex_digit_to_int( char c )
	{
		if ( char_is_digit( c ) )
			return digit_to_int( c );
		else if ( is_between( c, 'a', 'f' ) )
			return c - 'a' + 10;
		else if ( is_between( c, 'A', 'F' ) )
			return c - 'A' + 10;
		return -1;
	}

	GEN_IMPL_INLINE s32 str_compare( const char* s1, const char* s2 )
	{
		while ( *s1 && ( *s1 == *s2 ) )
		{
			s1++, s2++;
		}
		return *( u8* )s1 - *( u8* )s2;
	}

	GEN_IMPL_INLINE s32 str_compare( const char* s1, const char* s2, sw len )
	{
		for ( ; len > 0; s1++, s2++, len-- )
		{
			if ( *s1 != *s2 )
				return ( ( s1 < s2 ) ? -1 : +1 );
			else if ( *s1 == '\0' )
				return 0;
		}
		return 0;
	}

	GEN_IMPL_INLINE char* str_copy( char* dest, const char* source, sw len )
	{
		GEN_ASSERT_NOT_NULL( dest );
		if ( source )
		{
			char* str = dest;
			while ( len > 0 && *source )
			{
				*str++ = *source++;
				len--;
			}
			while ( len > 0 )
			{
				*str++ = '\0';
				len--;
			}
		}
		return dest;
	}

	GEN_IMPL_INLINE sw str_copy_nulpad( char* dest, const char* source, sw len )
	{
		sw result = 0;
		GEN_ASSERT_NOT_NULL( dest );
		if ( source )
		{
			const char* source_start = source;
			char*       str          = dest;
			while ( len > 0 && *source )
			{
				*str++ = *source++;
				len--;
			}
			while ( len > 0 )
			{
				*str++ = '\0';
				len--;
			}

			result = source - source_start;
		}
		return result;
	}

	GEN_IMPL_INLINE sw str_len( const char* str )
	{
		if ( str == NULL )
		{
			return 0;
		}
		const char* p = str;
		while ( *str )
			str++;
		return str - p;
	}

	GEN_IMPL_INLINE sw str_len( const char* str, sw max_len )
	{
		const char* end = zpl_cast( const char* ) mem_find( str, 0, max_len );
		if ( end )
			return end - str;
		return max_len;
	}

	GEN_IMPL_INLINE char* str_reverse( char* str )
	{
		sw    len  = str_len( str );
		char* a    = str + 0;
		char* b    = str + len - 1;
		len       /= 2;
		while ( len-- )
		{
			swap( char, *a, *b );
			a++, b--;
		}
		return str;
	}

	GEN_IMPL_INLINE void str_to_lower( char* str )
	{
		if ( ! str )
			return;
		while ( *str )
		{
			*str = char_to_lower( *str );
			str++;
		}
	}

	GEN_IMPL_INLINE void str_to_upper( char* str )
	{
		if ( ! str )
			return;
		while ( *str )
		{
			*str = char_to_upper( *str );
			str++;
		}
	}
	#pragma endregion String Ops

	#pragma region Containers
	#pragma push_macro("template")
	#undef template

	template<class Type>
	struct Array
	{
		struct Header
		{
			AllocatorInfo Allocator;
			uw            Capacity;
			uw            Num;
		};

		static
		Array init( AllocatorInfo allocator )
		{
			return init_reserve( allocator, grow_formula(0) );
		}

		static
		Array init_reserve( AllocatorInfo allocator, sw capacity )
		{
			Header* header = rcast( Header*, alloc( allocator, sizeof(Header) + sizeof(Type) * capacity ));

			if ( header == nullptr )
				return { nullptr };

			header->Allocator = allocator;
			header->Capacity  = capacity;
			header->Num       = 0;

			return { rcast( Type*, header + 1) };
		}

		static
		uw grow_formula( uw value )
		{
			return 2 * value + 8;
		}

		bool append( Type value )
		{
			Header* header = get_header();

			if ( header->Num == header->Capacity )
			{
				if ( ! grow( header->Capacity ))
					return false;

				header = get_header();
			}

			Data[ header->Num ] = value;
			header->Num++;

			return true;
		}

		Type& back( void )
		{
			Header& header = * get_header();
			return Data[ header.Num - 1 ];
		}

		void clear( void )
		{
			Header& header = * get_header();
			header.Num     = 0;
		}

		bool fill( uw begin, uw end, Type value )
		{
			Header& header = * get_header();

			if ( begin < 0 || end >= header.Num )
				return false;

			for ( sw idx = begin; idx < end; idx++ )
			{
				Data[ idx ] = value;
			}

			return true;
		}

		void free( void )
		{
			Header& header = * get_header();
			gen::free( header.Allocator, &header );
		}

		Header* get_header( void )
		{
			return rcast( Header*, Data ) - 1 ;
		}

		bool grow( uw min_capacity )
		{
			Header& header       = * get_header();
			uw      new_capacity = grow_formula( header.Capacity );

			if ( new_capacity < min_capacity )
				new_capacity = min_capacity;

			return set_capacity( new_capacity );
		}

		uw num( void )
		{
			return get_header()->Num;
		}

		bool pop( void )
		{
			Header& header = * get_header();

			GEN_ASSERT( header.Num > 0 );
			header.Num--;
		}

		void remove_at( uw idx )
		{
			Header* header = get_header();
			GEN_ASSERT( idx < header->Num );

			mem_move( header + idx, header + idx + 1, sizeof( Type ) * ( header->Num - idx - 1 ) );
			header->Num--;
		}

		bool reserve( uw new_capacity )
		{
			Header& header = * get_header();

			if ( header.Capacity < new_capacity )
				return set_capacity( new_capacity );

			return true;
		}

		bool resize( uw num )
		{
			Header* header = get_header();

			if ( header->Capacity < num )
			{
				if ( ! grow( num ) )
					return false;

				header = get_header();
			}

			header->Num = num;
			return true;
		}

		bool set_capacity( uw new_capacity )
		{
			Header& header = * get_header();

			if ( new_capacity == header.Capacity )
				return true;

			if ( new_capacity < header.Num )
				header.Num = new_capacity;

			sw      size       = sizeof( Header ) + sizeof( Type ) * new_capacity;
			Header* new_header = rcast( Header*, alloc( header.Allocator, size ) );

			if ( new_header == nullptr )
				return false;

			mem_move( new_header, &header, sizeof( Header ) + sizeof( Type ) * header.Num );

			new_header->Capacity = new_capacity;

			gen::free( header.Allocator, &header );

			Data = rcast( Type*, new_header + 1);
			return true;
		}

		Type* Data;

		operator Type*()
		{
			return Data;
		}

		operator Type const*() const
		{
			return Data;
		}

		// For-range based support

		Type* begin()
		{
			return Data;
		}

		Type* end()
		{
			return Data + get_header()->Num;
		}
	};

	template<typename Type>
	struct HashTable
	{
		struct FindResult
		{
			sw HashIndex;
			sw PrevIndex;
			sw EntryIndex;
		};

		struct Entry
		{
			u64  Key;
			sw   Next;
			Type Value;
		};

		static
		HashTable init( AllocatorInfo allocator )
		{
			HashTable<Type> result = { { nullptr }, { nullptr } };

			result.Hashes  = Array<sw>::init( allocator );
			result.Entries = Array<Entry>::init( allocator );

			return result;
		}

		static
		HashTable init_reserve( AllocatorInfo allocator, sw num )
		{
			HashTable<Type> result = { { nullptr }, { nullptr } };

			result.Hashes  = Array<sw>::init_reserve( allocator, num );
			result.Hashes.get_header()->Num = num;

			result.Entries = Array<Entry>::init_reserve( allocator, num );

			return result;
		}

		void clear( void )
		{
			for ( sw idx = 0; idx < Hashes.num(); idx++ )
				Hashes[ idx ] = -1;

			Hashes.clear();
			Entries.clear();
		}

		void destroy( void )
		{
			if ( Hashes && Hashes.get_header()->Capacity )
				Hashes.free();
			if ( Entries && Hashes.get_header()->Capacity )
				Entries.free();
		}

		Type* get( u64 key )
		{
			sw idx = find( key ).EntryIndex;
			if ( idx >= 0 )
				return & Entries[ idx ].Value;

			return nullptr;
		}

		using MapProc = void (*)( u64 key, Type  value );

		void map( MapProc map_proc )
		{
			GEN_ASSERT_NOT_NULL( map_proc );

			for ( sw idx = 0; idx < Entries.num(); idx++ )
			{
				map_proc( Entries[ idx ].Key, Entries[ idx ].Value );
			}
		}

		using MapMutProc = void (*)( u64 key, Type* value );

		void map_mut( MapMutProc map_proc )
		{
			GEN_ASSERT_NOT_NULL( map_proc );

			for ( sw idx = 0; idx < Entries.num(); idx++ )
			{
				map_proc( Entries[ idx ].Key, & Entries[ idx ].Value );
			}
		}

		void grow()
		{
			sw new_num = Array<Entry>::grow_formula( Entries.num() );
			rehash( new_num );
		}

		void rehash( sw new_num )
		{
			sw idx;
			sw last_added_index;

			HashTable<Type> new_ht = init_reserve( Hashes.get_header()->Allocator, new_num );

			Array<sw>::Header* hash_header = new_ht.Hashes.get_header();

			for ( idx = 0; idx < new_ht.Hashes.num(); ++idx )
				new_ht.Hashes[ idx ] = -1;

			for ( idx = 0; idx < Entries.num(); ++idx )
			{
				Entry& entry = Entries[ idx ];

				FindResult find_result;

				if ( new_ht.Hashes.num() == 0 )
					new_ht.grow();

				entry            = Entries[ idx ];
				find_result      = new_ht.find( entry.Key );
				last_added_index = new_ht.add_entry( entry.Key );

				if ( find_result.PrevIndex < 0 )
					new_ht.Hashes[ find_result.HashIndex ] = last_added_index;

				else
					new_ht.Entries[ find_result.PrevIndex ].Next = last_added_index;

				new_ht.Entries[ last_added_index ].Next  = find_result.EntryIndex;
				new_ht.Entries[ last_added_index ].Value = entry.Value;
			}

			destroy();
			*this = new_ht;
		}

		void rehash_fast()
		{
			sw idx;

			for ( idx = 0; idx < Entries.num(); idx++ )
				Entries[ idx ].Next = -1;

			for ( idx = 0; idx < Hashes.num(); idx++ )
				Hashes[ idx ] = -1;

			for ( idx = 0; idx < Entries.num(); idx++ )
			{
				Entry* entry;

				FindResult find_result;
			}
		}

		void remove( u64 key )
		{
			FindResult find_result = find( key);

			if ( find_result.EntryIndex >= 0 )
			{
				Entries.remove_at( find_result.EntryIndex );
				rehash_fast();
			}
		}

		void remove_entry( sw idx )
		{
			Entries.remove_at( idx );
		}

		void set( u64 key, Type value )
		{
			sw idx;
			FindResult find_result;

			if ( Hashes.num() == 0 )
				grow();

			find_result = find( key );

			if ( find_result.EntryIndex >= 0 )
			{
				idx = find_result.EntryIndex;
			}
			else
			{
				idx = add_entry( key );

				if ( find_result.PrevIndex >= 0 )
				{
					Entries[ find_result.PrevIndex ].Next = idx;
				}
				else
				{
					Hashes[ find_result.HashIndex ] = idx;
				}
			}

			Entries[ idx ].Value = value;

			if ( full() )
				grow();
		}

		sw slot( u64 key )
		{
			for ( sw idx = 0; idx < Hashes.num(); ++idx )
				if ( Hashes[ idx ] == key )
					return idx;

			return -1;
		}

		Array< sw>    Hashes;
		Array< Entry> Entries;

	protected:

		sw add_entry( u64 key )
		{
			sw idx;
			Entry entry = { key, -1 };

			idx = Entries.num();
			Entries.append( entry );
			return idx;
		}

		FindResult find( u64 key )
		{
			FindResult result = { -1, -1, -1 };

			if ( Hashes.num() > 0 )
			{
				result.HashIndex    = key % Hashes.num();
				result.EntryIndex  = Hashes[ result.HashIndex ];

				while ( result.EntryIndex >= 0 )
				{
					if ( Entries[ result.EntryIndex ].Key == key )
						break;

					result.PrevIndex  = result.EntryIndex;
					result.EntryIndex = Entries[ result.EntryIndex ].Next;
				}
			}

			return result;
		}

		b32 full()
		{
			return 0.75f * Hashes.num() < Entries.num();
		}
	};

	#pragma pop_macro("template")
	#pragma endregion Containers

	#pragma region Hashing

	u32 crc32( void const* data, sw len );

	#pragma endregion Hashing

	#pragma region String
		// Constant string with length.
		struct StrC
		{
			sw          Len;
			char const* Ptr;

			operator char const* () const
			{
				return Ptr;
			}
		};

		#define txt_StrC( text ) \
			(StrC){ sizeof( text ) - 1, text }

		StrC to_StrC( char const* str )
		{
			return { str_len( str ), str };
		}

		// Dynamic String
		// This is directly based off the ZPL string api.
		// They used a header pattern
		// I kept it for simplicty of porting but its not necessary to keep it that way.
		struct String
		{
			struct Header
			{
				AllocatorInfo Allocator;
				sw            Length;
				sw            Capacity;
			};

			static
			String make( AllocatorInfo allocator, char const* str )
			{
				sw length = str ? str_len( str ) : 0;
				return make_length( allocator, str, length );
			}

			static
			String make( AllocatorInfo allocator, StrC str )
			{
				return make_length( allocator, str.Ptr, str.Len );
			}

			static
			String make_reserve( AllocatorInfo allocator, sw capacity )
			{
				constexpr sw header_size = sizeof( Header );

				s32   alloc_size = header_size + capacity + 1;
				void* allocation = alloc( allocator, alloc_size );

				if ( allocation == nullptr )
					return { nullptr };

				mem_set( allocation, 0, alloc_size );

				Header*
				header            = rcast(Header*, allocation);
				header->Allocator = allocator;
				header->Capacity  = capacity;
				header->Length    = 0;

				String result = { (char*)allocation + header_size };
				return result;
			}

			static
			String make_length( AllocatorInfo allocator, char const* str, sw length )
			{
				constexpr sw header_size = sizeof( Header );

				s32   alloc_size = header_size + length + 1;
				void* allocation = alloc( allocator, alloc_size );

				if ( allocation == nullptr )
					return { nullptr };

				if ( ! str )
					mem_set( allocation, 0, alloc_size );

				Header&
				header = * rcast(Header*, allocation);
				header = { allocator, length, length };

				String  result = { rcast( char*, allocation) + header_size };

				if ( length && str )
					mem_copy( result, str, length );

				result[ length ] = '\0';

				return result;
			}

			static
			String fmt( AllocatorInfo allocator, char* buf, sw buf_size, char const* fmt, ... );

			static
			String fmt_buf( AllocatorInfo allocator, char const* fmt, ... );

			static
			String join( AllocatorInfo allocator, char const** parts, sw num_parts, char const* glue )
			{
				String result = make( allocator, "" );

				for ( sw idx = 0; idx < num_parts; ++idx )
				{
					result.append( parts[ idx ] );

					if ( idx < num_parts - 1 )
						result.append( glue );
				}

				return result;
			}

			static
			bool are_equal( String lhs, String rhs )
			{
				if ( lhs.length() != rhs.length() )
					return false;

				for ( sw idx = 0; idx < lhs.length(); ++idx )
					if ( lhs[ idx ] != rhs[ idx ] )
						return false;

				return true;
			}

			bool make_space_for( char const* str, sw add_len )
			{
				sw available = avail_space();

				// NOTE: Return if there is enough space left
				if ( available >= add_len )
				{
					return true;
				}
				else
				{
					sw new_len, old_size, new_size;

					void* ptr;
					void* new_ptr;

					AllocatorInfo allocator = get_header().Allocator;
					Header*       header	= nullptr;

					new_len  = length() + add_len;
					ptr      = & get_header();
					old_size = size_of( Header ) + length() + 1;
					new_size = size_of( Header ) + new_len + 1;

					new_ptr = resize( allocator, ptr, old_size, new_size );

					if ( new_ptr == nullptr )
						return false;

					header            = zpl_cast( Header* ) new_ptr;
					header->Allocator = allocator;
					header->Capacity  = new_len;

					Data = rcast( char*, header + 1 );

					return str;
				}
			}

			bool append( char const* str )
			{
				return append( str, str_len( str ) );
			}

			bool append( char const* str, sw length )
			{
				if ( sptr(str) > 0 )
				{
					sw curr_len = this->length();

					if ( ! make_space_for( str, length ) )
						return false;

					Header& header = get_header();

					mem_copy( Data + curr_len, str, length );

					Data[ curr_len + length ] = '\0';

					header.Length = curr_len + length;
				}

				return str;
			}

			bool append( StrC str)
			{
				return append( str.Ptr, str.Len );
			}

			bool append( const String other )
			{
				return append( other.Data, other.length() );
			}

			bool append_fmt( char const* fmt, ... );

			sw avail_space() const
			{
				Header const&
				header = * rcast( Header const*, Data - sizeof( Header ));

				return header.Capacity - header.Length;
			}

			sw capacity() const
			{
				Header const&
				header = * rcast( Header const*, Data - sizeof( Header ));

				return header.Capacity;
			}

			void clear()
			{
				get_header().Length = 0;
			}

			String duplicate( AllocatorInfo allocator )
			{
				return make_length( allocator, Data, length() );
			}

			void free()
			{
				if ( ! Data )
					return;

				Header& header = get_header();

				gen::free( header.Allocator, & header );
			}

			Header& get_header()
			{
				return *(Header*)(Data - sizeof(Header));
			}

			sw length() const
			{
				Header const&
				header = * rcast( Header const*, Data - sizeof( Header ));

				return header.Length;
			}

			void trim( char const* cut_set )
			{
				sw len = 0;

				char* start_pos = Data;
				char* end_pos   = Data + length() - 1;

				while ( start_pos <= end_pos && char_first_occurence( cut_set, *start_pos ) )
					start_pos++;

				while ( end_pos > start_pos && char_first_occurence( cut_set, *end_pos ) )
					end_pos--;

				len = scast( sw, ( start_pos > end_pos ) ? 0 : ( ( end_pos - start_pos ) + 1 ) );

				if ( Data != start_pos )
					mem_move( Data, start_pos, len );

				Data[ len ] = '\0';

				get_header().Length = len;
			}

			void trim_space()
			{
				return trim( " \t\r\n\v\f" );
			}

			// For-range support

			char* begin()
			{
				return Data;
			}

			char* end()
			{
				Header const&
				header = * rcast( Header const*, Data - sizeof( Header ));

				return Data + header.Length;
			}

			operator bool()
			{
				return Data;
			}

			operator char* ()
			{
				return Data;
			}

			operator char const* () const
			{
				return Data;
			}

			operator StrC() const
			{
				return
				{
					length(),
					Data
				};
			}

			// Used with cached strings
			// Essentially makes the string a string view.
			String const& operator = ( String const& other ) const
			{
				if ( this == & other )
					return *this;

				String& this_ = ccast( String, *this );

				this_.Data = other.Data;

				return this_;
			}

			char& operator [] ( sw index )
			{
				return Data[ index ];
			}

			char const& operator [] ( sw index ) const
			{
				return Data[ index ];
			}

			char* Data = nullptr;
		};

		struct String_POD
		{
			char* Data;

			operator String()
			{
				return * rcast(String*, this);
			}
		};
		static_assert( sizeof( String_POD ) == sizeof( String ), "String is not a POD" );
	#pragma endregion String

	#pragma region File Handling

	typedef u32 FileMode;

	enum FileModeFlag
	{
		EFileMode_READ   = bit( 0 ),
		EFileMode_WRITE  = bit( 1 ),
		EFileMode_APPEND = bit( 2 ),
		EFileMode_RW     = bit( 3 ),
		GEN_FILE_MODES   = EFileMode_READ | EFileMode_WRITE | EFileMode_APPEND | EFileMode_RW,
	};

	// NOTE: Only used internally and for the file operations
	enum SeekWhenceType
	{
		ESeekWhence_BEGIN   = 0,
		ESeekWhence_CURRENT = 1,
		ESeekWhence_END     = 2,
	};

	enum FileError
	{
		EFileError_NONE,
		EFileError_INVALID,
		EFileError_INVALID_FILENAME,
		EFileError_EXISTS,
		EFileError_NOT_EXISTS,
		EFileError_PERMISSION,
		EFileError_TRUNCATION_FAILURE,
		EFileError_NOT_EMPTY,
		EFileError_NAME_TOO_LONG,
		EFileError_UNKNOWN,
	};

	union FileDescriptor
	{
		void* p;
		sptr  i;
		uptr  u;
	};

	typedef struct FileOperations FileOperations;

	#define GEN_FILE_OPEN_PROC( name )     FileError name( FileDescriptor* fd, FileOperations* ops, FileMode mode, char const* filename )
	#define GEN_FILE_READ_AT_PROC( name )  b32 name( FileDescriptor fd, void* buffer, sw size, s64 offset, sw* bytes_read, b32 stop_at_newline )
	#define GEN_FILE_WRITE_AT_PROC( name ) b32 name( FileDescriptor fd, void const* buffer, sw size, s64 offset, sw* bytes_written )
	#define GEN_FILE_SEEK_PROC( name )     b32 name( FileDescriptor fd, s64 offset, SeekWhenceType whence, s64* new_offset )
	#define GEN_FILE_CLOSE_PROC( name )    void name( FileDescriptor fd )

	typedef GEN_FILE_OPEN_PROC( file_open_proc );
	typedef GEN_FILE_READ_AT_PROC( FileReadProc );
	typedef GEN_FILE_WRITE_AT_PROC( FileWriteProc );
	typedef GEN_FILE_SEEK_PROC( FileSeekProc );
	typedef GEN_FILE_CLOSE_PROC( FileCloseProc );

	struct FileOperations
	{
		FileReadProc*  read_at;
		FileWriteProc* write_at;
		FileSeekProc*  seek;
		FileCloseProc* close;
	};

	extern FileOperations const default_file_operations;

	typedef u64 FileTime;

	enum DirType
	{
		GEN_DIR_TYPE_FILE,
		GEN_DIR_TYPE_FOLDER,
		GEN_DIR_TYPE_UNKNOWN,
	};

	struct DirInfo;

	struct DirEntry
	{
		char const* FileName;
		DirInfo*    Info;
		u8          Type;
	};

	struct DirInfo
	{
		char const* FullPath;
		DirEntry*   Entries;    // zpl_array

		// Internals
		char** Filenames;    // zpl_array
		String Buffer;
	};

	struct FileInfo
	{
		FileOperations Ops;
		FileDescriptor FD;
		b32            IsTemp;

		char const* Filename;
		FileTime    LastWriteTime;
		DirEntry*   Dir;
	};

	enum FileStandardType
	{
		EFileStandard_INPUT,
		EFileStandard_OUTPUT,
		EFileStandard_ERROR,

		EFileStandard_COUNT,
	};

	/**
	 * Get standard file I/O.
	 * @param  std Check zpl_file_standard_type
	 * @return     File handle to standard I/O
	 */
	FileInfo* file_get_standard( FileStandardType std );

	/**
	 * Closes the file
	 * @param  file
	 */
	FileError file_close( FileInfo* file );

	/**
	 * Returns the currently opened file's name
	 * @param  file
	 */
	inline
	char const* file_name( FileInfo* file )
	{
		return file->Filename ? file->Filename : "";
	}

	/**
	 * Opens a file using a specified mode
	 * @param  file
	 * @param  mode     Access mode to use
	 * @param  filename
	 */
	FileError file_open_mode( FileInfo* file, FileMode mode, char const* filename );

	/**
	 * Seeks the file cursor from the beginning of file to a specific position
	 * @param  file
	 * @param  offset Offset to seek to
	 */
	GEN_DEF_INLINE s64 file_seek( FileInfo* file, s64 offset );

	/**
	 * Returns the length from the beginning of the file we've read so far
	 * @param  file
	 * @return      Our current position in file
	 */
	GEN_DEF_INLINE s64 file_tell( FileInfo* file );

	/**
	 * Writes to a file
	 * @param  file
	 * @param  buffer Buffer to read from
	 * @param  size   Size to read
	 */
	b32 file_write( FileInfo* file, void const* buffer, sw size );

	/**
	 * Writes to file at a specific offset
	 * @param  file
	 * @param  buffer        Buffer to read from
	 * @param  size          Size to write
	 * @param  offset        Offset to write to
	 * @param  bytes_written How much data we've actually written
	 */
	GEN_DEF_INLINE b32 file_write_at( FileInfo* file, void const* buffer, sw size, s64 offset );

	/**
	 * Writes to file safely
	 * @param  file
	 * @param  buffer        Buffer to read from
	 * @param  size          Size to write
	 * @param  offset        Offset to write to
	 * @param  bytes_written How much data we've actually written
	 */
	GEN_DEF_INLINE b32 file_write_at_check( FileInfo* file, void const* buffer, sw size, s64 offset, sw* bytes_written );

	GEN_IMPL_INLINE s64 file_seek( FileInfo* f, s64 offset )
	{
		s64 new_offset = 0;

		if ( ! f->Ops.read_at )
			f->Ops = default_file_operations;

		f->Ops.seek( f->FD, offset, ESeekWhence_BEGIN, &new_offset );

		return new_offset;
	}

	GEN_IMPL_INLINE s64 file_tell( FileInfo* f )
	{
		s64 new_offset = 0;

		if ( ! f->Ops.read_at )
			f->Ops = default_file_operations;

		f->Ops.seek( f->FD, 0, ESeekWhence_CURRENT, &new_offset );

		return new_offset;
	}

	GEN_IMPL_INLINE b32 file_write( FileInfo* f, void const* buffer, sw size )
	{
		s64 cur_offset = file_tell( f );
		b32 result     = file_write_at( f, buffer, size, file_tell( f ) );

		file_seek( f, cur_offset + size );

		return result;
	}

	GEN_IMPL_INLINE b32 file_write_at( FileInfo* f, void const* buffer, sw size, s64 offset )
	{
		return file_write_at_check( f, buffer, size, offset, NULL );
	}

	GEN_IMPL_INLINE b32 file_write_at_check( FileInfo* f, void const* buffer, sw size, s64 offset, sw* bytes_written )
	{
		if ( ! f->Ops.read_at )
			f->Ops = default_file_operations;

		return f->Ops.write_at( f->FD, buffer, size, offset, bytes_written );
	}
	#pragma endregion File Handling

	#pragma region Printing

	#ifndef GEN_PRINTF_MAXLEN
	#	define GEN_PRINTF_MAXLEN 65536
	#endif

	// NOTE: A locally persisting buffer is used internally
	char* str_fmt_buf( char const* fmt, ... );
	char* str_fmt_buf_va( char const* fmt, va_list va );
	sw    str_fmt_va( char* str, sw n, char const* fmt, va_list va );
	sw    str_fmt_out_va( char const* fmt, va_list va );
	sw    str_fmt_out_err( char const* fmt, ... );
	sw    str_fmt_out_err_va( char const* fmt, va_list va );
	sw    str_fmt_file_va( FileInfo* f, char const* fmt, va_list va );
	#pragma endregion Printing

	namespace Memory
	{
		// NOTE: This limits the size of the string that can be read from a file or generated to 10 megs.
		// If you are generating a string larger than this, increase the size of the bucket here.
		constexpr uw BucketSize = megabytes(10);

		// Global allocator used for data with process lifetime.
		extern AllocatorInfo GlobalAllocator;

		// Heap allocator is being used for now to isolate errors from being memory related (tech debt till ready to address)
		// #define g_allocator heap()

		void setup();
		void cleanup();
	}

	inline
	sw log_fmt(char const* fmt, ...)
	{
		sw res;
		va_list va;

		va_start(va, fmt);
		res = str_fmt_out_va(fmt, va);
		va_end(va);

		return res;
	}

	inline
	sw fatal(char const* fmt, ...)
	{
		local_persist thread_local
		char buf[GEN_PRINTF_MAXLEN] = { 0 };

		va_list va;

	#if Build_Debug
		va_start(va, fmt);
		str_fmt_va(buf, GEN_PRINTF_MAXLEN, fmt, va);
		va_end(va);

		assert_crash(buf);
		return -1;
	#else
		va_start(va, fmt);
		str_fmt_out_err_va( fmt, va);
		va_end(va);

		exit(1);
		return -1;
	#endif
	}

// gen namespace
}
//END: GENCPP_PROVIDE_DEPENDENCIES
#endif
#pragma endregion GENCPP DEPENDENCIES

namespace gen
{
	using LogFailType = sw(*)(char const*, ...);

	// By default this library will either crash or exit if an error is detected while generating codes.
	// Even if set to not use fatal, fatal will still be used for memory failures as the library is unusable when they occur.
#	ifdef GEN_DONT_USE_FATAL
		constexpr LogFailType log_failure = log_fmt;
#	else
		constexpr LogFailType log_failure = fatal;
#	endif

	namespace ECode
	{
	#	define Define_Types           \
		Entry( Untyped )              \
		Entry( Comment )              \
		Entry( Access_Private )       \
		Entry( Access_Protected )     \
		Entry( Access_Public )        \
		Entry( Attributes )           \
		Entry( Class )                \
		Entry( Class_Fwd )            \
		Entry( Class_Body )           \
		Entry( Enum )                 \
		Entry( Enum_Fwd )             \
		Entry( Enum_Body )            \
		Entry( Enum_Class )           \
		Entry( Enum_Class_Fwd )       \
		Entry( Execution )            \
		Entry( Export_Body )          \
		Entry( Extern_Linkage )       \
		Entry( Extern_Linkage_Body )  \
		Entry( Friend )               \
		Entry( Function )             \
		Entry( Function_Fwd )         \
		Entry( Function_Body )        \
		Entry( Global_Body )          \
		Entry( Module )               \
		Entry( Namespace )            \
		Entry( Namespace_Body )       \
		Entry( Operator )             \
		Entry( Operator_Fwd )         \
		Entry( Operator_Member )      \
		Entry( Operator_Member_Fwd )  \
		Entry( Operator_Cast )		  \
		Entry( Operator_Cast_Fwd )    \
		Entry( Parameters )           \
		Entry( Preprocessor_Include ) \
		Entry( Specifiers )           \
		Entry( Struct )               \
		Entry( Struct_Fwd )           \
		Entry( Struct_Body )          \
		Entry( Template )             \
		Entry( Typedef )              \
		Entry( Typename )             \
		Entry( Union )			      \
		Entry( Union_Body) 		      \
		Entry( Using )                \
		Entry( Using_Namespace )      \
		Entry( Variable )

		enum Type : u32
		{
		#	define Entry( Type ) Type,
			Define_Types
		#	undef Entry

			Num_Types,
			Invalid
		};

		inline
		StrC to_str( Type type )
		{
			static
			StrC lookup[Num_Types] = {
			#	define Entry( Type ) { sizeof(stringize(Type)), stringize(Type) },
				Define_Types
			#	undef Entry
			};

			return lookup[ type ];
		}

	#	undef Define_Types
	}
	using CodeT = ECode::Type;

	// Used to indicate if enum definitoin is an enum class or regular enum.
	enum class EnumT : u8
	{
		Regular,
		Class
	};

	constexpr EnumT EnumClass   = EnumT::Class;
	constexpr EnumT EnumRegular = EnumT::Regular;

	enum class UsingT : u8
	{
		Regular,
		Namespace
	};

	constexpr UsingT UsingRegular   = UsingT::Regular;
	constexpr UsingT UsingNamespace = UsingT::Namespace;

	namespace EOperator
	{
	#	define Define_Operators       \
		Entry( Assign,          =  )  \
		Entry( Assign_Add,      += )  \
		Entry( Assign_Subtract, -= )  \
		Entry( Assign_Multiply, *= )  \
		Entry( Assign_Divide,   /= )  \
		Entry( Assign_Modulo,   %= )  \
		Entry( Assign_BAnd,     &= )  \
		Entry( Assign_BOr,      |= )  \
		Entry( Assign_BXOr,     ^= )  \
		Entry( Assign_LShift,   <<= ) \
		Entry( Assign_RShift,   >>= ) \
		Entry( Increment,       ++ )  \
		Entry( Decrement,       -- )  \
		Entry( Unary_Plus,      + )   \
		Entry( Unary_Minus,     - )   \
		Entry( UnaryNot,        ! )   \
		Entry( Add,             + )   \
		Entry( Subtract,        - )   \
		Entry( Multiply,        * )   \
		Entry( Divide,          / )   \
		Entry( Modulo,          % )   \
		Entry( BNot,            ~ )   \
		Entry( BAnd,            & )   \
		Entry( BOr,             | )   \
		Entry( BXOr,            ^ )   \
		Entry( LShift,          << )  \
		Entry( RShift,          >> )  \
		Entry( LAnd,            && )  \
		Entry( LOr,             || )  \
		Entry( LEqual,          == )  \
		Entry( LNot,            != )  \
		Entry( Lesser,          < )   \
		Entry( Greater,         > )   \
		Entry( LesserEqual,     <= )  \
		Entry( GreaterEqual,    >= )  \
		Entry( Subscript,       [] )  \
		Entry( Indirection,     * )   \
		Entry( AddressOf,       & )   \
		Entry( MemberOfPointer, -> )  \
		Entry( PtrToMemOfPtr,   ->* ) \
		Entry( FunctionCall,    () )

		enum Type : u32
		{
		#	define Entry( Type_, Token_ ) Type_,
			Define_Operators
		#	undef Entry
			Comma,

			Num_Ops,
			Invalid
		};

		inline
		char const* to_str( Type op )
		{
			local_persist
			char const* lookup[ Num_Ops ] = {
			#	define Entry( Type_, Token_ ) stringize(Token_),
				Define_Operators
			#	undef Entry
				","
			};

			return lookup[ op ];
		}

	#	undef Define_Operators
	}
	using OperatorT = EOperator::Type;

	namespace ESpecifier
	{
	/*
		Note: The following are handled separately:
		attributes
		alignas
	*/

	#	define Define_Specifiers                    \
		Entry( Invalid,          INVALID )           \
		Entry( Const,            const )             \
		Entry( Consteval,        consteval )         \
		Entry( Constexpr,        constexpr )         \
		Entry( Constinit,        constinit )         \
		Entry( External_Linkage, extern )            \
		Entry( Global,           global )            \
		Entry( Inline,           inline )            \
		Entry( Internal_Linkage, internal )          \
		Entry( Local_Persist,    local_persist )     \
		Entry( Mutable,          mutable )           \
		Entry( Ptr,              * )                 \
		Entry( Ref,              & )                 \
		Entry( Register,         register )          \
		Entry( RValue,           && )                \
		Entry( Static_Member,    static  )           \
		Entry( Thread_Local,     thread_local )      \
		Entry( Volatile,         volatile )

		enum Type : u32
		{
		#	define Entry( Specifier, Code ) Specifier,
			Define_Specifiers
		#	undef Entry

			Num_Specifiers,
		};

		// Specifier to string
		inline
		StrC to_str( Type specifier )
		{
			local_persist
			StrC lookup[ Num_Specifiers ] = {
			#	pragma push_macro( "global" )
			#	pragma push_macro( "internal" )
			#	pragma push_macro( "local_persist" )
			#	define global        global
			#	define internal      internal
			#	define local_persist local_persist

			#	define Entry( Spec_, Code_ ) { sizeof(stringize(Code_)), stringize(Code_) },
				Define_Specifiers
			#	undef Entry

			#	pragma pop_macro( "global" )
			#	pragma pop_macro( "internal" )
			#	pragma pop_macro( "local_persist" )
			};

			return lookup[ specifier ];
		}

		inline
		Type to_type( StrC str )
		{
			local_persist
			u32 keymap[ Num_Specifiers ];
			do_once_start
				for ( u32 index = 0; index < Num_Specifiers; index++ )
				{
					StrC enum_str = to_str( (Type)index );

					// We subtract 1 to remove the null terminator
					// This is because the tokens lexed are not null terminated.
					keymap[index] = crc32( enum_str.Ptr, enum_str.Len - 1);
				}
			do_once_end

			u32 hash = crc32( str.Ptr, str.Len );

			for ( u32 index = 0; index < Num_Specifiers; index++ )
			{
				if ( keymap[index] == hash )
					return (Type)index;
			}

			return Invalid;
		}

	#	undef Define_Specifiers
	}
	using SpecifierT = ESpecifier::Type;

	enum class AccessSpec : u32
	{
		Default,
		Public,
		Protected,
		Private,

		Num_AccessSpec,
		Invalid,
	};

	inline
	char const* to_str( AccessSpec type )
	{
		local_persist
		char const* lookup[ (u32)AccessSpec::Num_AccessSpec ] = {
			"",
			"public",
			"protected",
			"private",
		};

		if ( type > AccessSpec::Public )
			return "Invalid";

		return lookup[ (u32)type ];
	}

	enum class ModuleFlag : u32
	{
		None    = 0,
		Export  = bit(0),
		Import  = bit(1),
		// Private = bit(2),

		Num_ModuleFlags,
		Invalid,
	};

	ModuleFlag operator|( ModuleFlag A, ModuleFlag B)
	{
		return (ModuleFlag)( (u32)A | (u32)B );
	}

	/*
		Predefined attributes

		Used for the parser constructors to identify non-standard attributes
	*/
	namespace Attribute
	{
	#if defined(GEN_SYSTEM_WINDOWS) || defined( __CYGWIN__ )
	#	define GEN_API_
	#	define GEN_API_Export_Code   __declspec(dllexport)
	#	define GEN_API_Import_Code   __declspec(dllimport)
	#	define GEN_Attribute_Keyword __declspec

		constexpr char const* API_Export = stringize( GEN_API_Export_Code  );
		constexpr char const* API_Import = stringize( GEN_API_Import_Code  );
		constexpr char const* Keyword    = stringize( GEN_Attribute_Keyword);

	#elif GEN_HAS_ATTRIBUTE( visibility ) || GEN_GCC_VERSION_CHECK( 3, 3, 0 ) || GEN_INTEL_VERSION_CHECK( 13, 0, 0 )
	#	define GEN_API_Export_Code   __attribute__ ((visibility ("default")))
	#	define GEN_API_Import_Code   __attribute__ ((visibility ("default")))
	#	define GEN_Attribute_Keyword __attribute__

		constexpr char const* API_Export = txt( GEN_API_Export_Code );
		constexpr char const* API_Import = txt( GEN_API_Import_Code );
		constexpr char const* Keyword    = txt( GEN_Attribute_Keyword);

	#else
	#	define GEN_API_Export_Code
	#	define GEN_API_Import_Code
	#	define GEN_Attribute_Keyword

		constexpr char const* API_Export = "";
		constexpr char const* API_Import = "";
		constexpr char const* Keyword    = "";
	#endif
	}

#pragma region Data Structures
	// Implements basic string interning. Data structure is based off the ZPL Hashtable.
	using StringTable = HashTable<String const>;

	// Represents strings cached with the string table.
	// Should never be modified, if changed string is desired, cache_string( str ) another.
	using StringCached = String const;

	// Desired width of the AST data structure.
	constexpr u32 AST_POD_Size = 256;

	// TODO: If perf needs it, convert layout an SOA format.
	/*
		Simple AST POD with functionality to seralize into C++ syntax.

		ASTs are currently stored as an AOS. They are always reconstructed on demand.
		Thus redundant AST can easily occur.
		Not sure if its better to store them in a hashmap.

		Any type specific functions assume the construction of the AST was done correctly.
	*/
	struct AST
	{
	#	pragma region Member Functions
		void add_entry( AST* other );

		AST* body()
		{
			return entry( 0 );
		}

		AST* duplicate();

		AST*& entry( u32 idx )
		{
			return DynamicEntries ? ArrDyn[ idx ] : ArrStatic[ idx ];
		}

		bool has_entries()
		{
			return num_entries();
		}

		bool is_invalid()
		{
			return Type != ECode::Invalid;
		}

		bool is_equal( AST* other );

		s32 num_entries()
		{
			return DynamicEntries ? ArrDyn.num() : StaticIndex;
		}

		// Parameter

		AST* get_param( s32 index )
		{
			if ( index <= 0 )
				return this;

			return entry( index + 1 );
		}

		s32 param_count()
		{
			// The first entry (which holds the type) represents the first parameter.
			return num_entries();
		}

		AST* param_type()
		{
			return entry( 0 );
		}

		// Specifiers

		bool add_specifier( SpecifierT spec )
		{
			if ( StaticIndex == AST::ArrSpecs_Cap )
			{
				log_failure("AST::add_specifier: Attempted to add over %d specifiers to a specifiers AST!", AST::ArrSpecs_Cap );
				return false;
			}

			ArrSpecs[ StaticIndex ] = spec;
			StaticIndex++;
			return true;
		}

		s32 has_specifier( SpecifierT spec )
		{
			for ( s32 idx = 0; idx < StaticIndex; idx++ )
			{
				if ( ArrSpecs[StaticIndex] == spec )
					return idx;
			}

			return -1;
		}

		// Typename

		bool typename_is_ptr()
		{
			assert_crash("not implemented");
			return false;
		}

		bool typename_is_ref()
		{
			assert_crash("not implemented");
			return false;
		}

		AST* typename_specifiers()
		{
			return entry( 0 );
		}

		// Serialization

		char const* debug_str()
		{
			char const* fmt = stringize(
				\nCode Debug:
				\nType    : %s
				\nParent  : %s
				\nName    : %s
				\nComment : %s
			);

			// These should be used immediately in a log.
			// Thus if its desired to keep the debug str
			// for multiple calls to bprintf,
			// allocate this to proper string.
			return str_fmt_buf( fmt
			,	type_str()
			,	Parent   ? Parent->Name : ""
			,	Name     ? Name         : ""
			);
		}

		char const* type_str()
		{
			return ECode::to_str( Type );
		}

		String to_string();
	#	pragma endregion Member Functions

		constexpr static
		uw ArrS_Cap =
		( 	AST_POD_Size
			- sizeof(AST*)         // Parent
			- sizeof(StringCached) // Name
			- sizeof(CodeT) 	   // Type
			- sizeof(OperatorT)    // Op
			- sizeof(ModuleFlag)   // ModuleFlags
			- sizeof(AccessSpec)   // ParentAccess
			- sizeof(u32) 		   // StaticIndex
			- sizeof(bool)         // DynamicEntries
			- sizeof(u8) * 3 )     // _Align_Pad
		/ sizeof(AST*);

		constexpr static
		uw ArrSpecs_Cap = ArrS_Cap * (sizeof(AST*) / sizeof(SpecifierT));

	#	define Using_AST_POD                           \
		union {                                        \
			AST*          ArrStatic[AST::ArrS_Cap];    \
			Array< AST* > ArrDyn;                      \
			StringCached  Content;                     \
			SpecifierT    ArrSpecs[AST::ArrSpecs_Cap]; \
		};                                             \
		AST*              Parent;                      \
		StringCached      Name;                        \
		CodeT             Type;                        \
		OperatorT         Op;                          \
		ModuleFlag        ModuleFlags;                 \
		AccessSpec        ParentAccess;				   \
		u32               StaticIndex;                 \
		bool              DynamicEntries;              \
		u8                _Align_Pad[3];

		Using_AST_POD
	};

	struct AST_POD
	{
		Using_AST_POD
	#	undef Using_CodePOD
	};

	// Its intended for the AST to have equivalent size to its POD.
	// All extra functionality within the AST namespace should just be syntatic sugar.
	static_assert( sizeof(AST)     == sizeof(AST_POD), "ERROR: AST IS NOT POD" );
	static_assert( sizeof(AST_POD) == AST_POD_Size,    "ERROR: AST POD is not size of AST_POD_Size" );

	/*
		AST* typedef as to not constantly have to add the '*' as this is written often..
	*/
	struct Code
	{
	#	pragma region Statics
		// Used to identify ASTs that should always be duplicated. (Global constant ASTs)
		static Code Global;

		// Used to identify invalid generated code.
		static Code Invalid;
	#	pragma endregion Statics

	#	pragma region Member Functions
		Code body()
		{
			if ( ast == nullptr )
			{
				log_failure("Code::body: AST is null!");
				return Invalid;
			}

			if ( ast->Type == ECode::Invalid )
			{
				log_failure("Code::body: Type is invalid, cannot get");
				return Invalid;
			}

			return { ast->body() };
		}

		String to_string() const
		{
			return ast->to_string();
		}

		void set_global()
		{
			if ( ast == nullptr )
			{
				log_failure("Code::set_global: Cannot set code as global, AST is null!");
				return;
			}

			ast->Parent = Global.ast;
		}

		bool is_valid()
		{
			// Originally intended to use operator bool(), however for some reason
			// The C++ standard has operator Type*() with higher precedence than operator bool().
			// Even when directly casting to bool. Amazing.
			return ast != nullptr && ast->Type != ECode::Invalid;
		}

		operator bool() const
		{
			return ast != nullptr && ast->Type != ECode::Invalid;
		}

		bool operator ==( Code other )
		{
			return ast == other.ast;
		}

		bool operator !=( Code other )
		{
			return ast != other.ast;
		}

		operator AST*()
		{
			return ast;
		}

		AST* operator->()
		{
			if ( ast == nullptr )
			{
				log_failure("Attempt to dereference a nullptr!");
				return nullptr;
			}

			return ast;
		}
	#	pragma endregion Member Functions

		AST* ast;
	};

	struct Code_POD
	{
		AST_POD* ast;
	};

	static_assert( sizeof(Code) == sizeof(Code_POD), "ERROR: Code is not POD" );

	// Used when the its desired when omission is allowed in a definition.
	constexpr Code NoCode = { nullptr };
#pragma endregion Data Structures

#pragma region Gen Interface
	// Initialize the library.
	// This currently just initializes the CodePool.
	void init();

	// Currently manually free's the arenas, code for checking for leaks.
	// However on Windows at least, it doesn't need to occur as the OS will clean up after the process.
	void deinit();

	// Used internally to retrive or make string allocations.
	// Strings are stored in a series of string arenas of fixed size (SizePer_StringArena)
	StringCached get_cached_string( StrC str );

	/*
		This provides a fresh Code AST.
		The gen interface use this as their method from getting a new AST object from the CodePool.
		Use this if you want to make your own API for formatting the supported Code Types.
	*/
	Code make_code();

	// This provides a fresh Code AST array for the entries field of the AST.
	// This is done separately from the regular CodePool allocator.
	Array< AST* > make_code_entries();

	// Set these before calling gen's init() procedure.
	// Data

	void set_allocator_data_arrays       ( AllocatorInfo data_array_allocator );
	void set_allocator_code_pool         ( AllocatorInfo pool_allocator );
	void set_allocator_code_enrties_arena( AllocatorInfo pool_allocator );
	void set_allocator_string_arena      ( AllocatorInfo string_allocator );
	void set_allocator_string_table      ( AllocatorInfo string_allocator );
	void set_allocator_type_table        ( AllocatorInfo type_reg_allocator );

#	pragma region Upfront
	Code def_attributes( StrC content );
	Code def_comment   ( StrC content );

	Code def_class( StrC name
		, Code body         = NoCode
		, Code parent       = NoCode, AccessSpec access = AccessSpec::Default
		, Code attributes   = NoCode
		, ModuleFlag mflags = ModuleFlag::None );

	Code def_enum( StrC
		, Code       body      = NoCode,      Code type       = NoCode
		, EnumT      specifier = EnumRegular, Code attributes = NoCode
		, ModuleFlag mflags    = ModuleFlag::None );

	Code def_execution  ( StrC content );
	Code def_extern_link( StrC name, Code body, ModuleFlag mflags = ModuleFlag::None );
	Code def_friend     ( Code symbol );

	Code def_function( StrC name
		, Code       params     = NoCode, Code ret_type   = NoCode, Code body = NoCode
		, Code       specifiers = NoCode, Code attributes = NoCode
		, ModuleFlag mflags     = ModuleFlag::None );

	Code def_include  ( StrC content );
	Code def_module   ( StrC name,            ModuleFlag mflags = ModuleFlag::None );
	Code def_namespace( StrC name, Code body, ModuleFlag mflags = ModuleFlag::None );

	Code def_operator( OperatorT op
		, Code       params     = NoCode, Code ret_type   = NoCode, Code body = NoCode
		, Code       specifiers = NoCode, Code attributes = NoCode
		, ModuleFlag mflags     = ModuleFlag::None );

	Code def_operator_cast( Code type, Code body = NoCode );

	Code def_param    ( Code type, StrC name, Code value = NoCode );
	Code def_specifier( SpecifierT specifier );

	Code def_struct( StrC name
		, Code       body
		, Code       parent     = NoCode, AccessSpec access = AccessSpec::Default
		, Code       attributes = NoCode
		, ModuleFlag mflags     = ModuleFlag::None );

	Code def_template( Code params, Code body, ModuleFlag mflags = ModuleFlag::None );

	Code def_type   ( StrC name, Code arrayexpr = NoCode, Code specifiers = NoCode, Code attributes = NoCode );
	Code def_typedef( StrC name, Code type, Code attributes = NoCode, ModuleFlag mflags = ModuleFlag::None );

	Code def_union( StrC name, Code body, Code attributes = NoCode, ModuleFlag mflags = ModuleFlag::None );

	Code def_using( StrC name, Code type = NoCode
		, Code       attributess = NoCode
		, ModuleFlag mflags      = ModuleFlag::None );

	Code def_using_namespace( StrC name );

	Code def_variable( Code type, StrC name, Code value = NoCode
		, Code       specifiers = NoCode, Code attributes = NoCode
		, ModuleFlag mflags     = ModuleFlag::None );

	Code def_class_body      ( s32 num, ... );
	Code def_enum_body       ( s32 num, ... );
	Code def_export_body     ( s32 num, ... );
	Code def_extern_link_body( s32 num, ... );
	Code def_function_body   ( s32 num, ... );
	Code def_global_body     ( s32 num, ... );
	Code def_namespace_body  ( s32 num, ... );
	Code def_params          ( s32 num, ... );
	Code def_specifiers      ( s32 num, ... );
	Code def_struct_body     ( s32 num, ... );
	Code def_union_body      ( s32 num, ... );
	Code def_class_body      ( s32 num, Code* codes );
	Code def_enum_body       ( s32 num, Code* codes );
	Code def_export_body     ( s32 num, Code* codes);
	Code def_extern_link_body( s32 num, Code* codes );
	Code def_function_body   ( s32 num, Code* codes );
	Code def_global_body     ( s32 num, Code* codes );
	Code def_namespace_body  ( s32 num, Code* codes );
	Code def_params          ( s32 num, Code* params );
	Code def_specifiers      ( s32 num, SpecifierT* specs );
	Code def_struct_body     ( s32 num, Code* codes );
	Code def_union_body      ( s32 num, Code* codes );

	// Use this to manually populate the entries on demand (will not be checked for validity).
	Code def_empty_body( CodeT body_type );
#	pragma endregion Upfront

#	pragma region Parsing
#	ifdef GEN_FEATURE_PARSING
	Code parse_class        ( StrC class_def     );
	Code parse_enum         ( StrC enum_def      );
	Code parse_export_body  ( StrC export_def    );
	Code parse_extern_link  ( StrC exten_link_def);
	Code parse_friend       ( StrC friend_def    );
	Code parse_function     ( StrC fn_def        );
	Code parse_global_body  ( StrC body_def      );
	Code parse_namespace    ( StrC namespace_def );
	Code parse_operator     ( StrC operator_def  );
	Code parse_operator_cast( StrC operator_def  );
	Code parse_struct       ( StrC struct_def    );
	Code parse_template     ( StrC template_def  );
	Code parse_type         ( StrC type_def      );
	Code parse_typedef      ( StrC typedef_def   );
	Code parse_union        ( StrC union_def     );
	Code parse_using        ( StrC using_def     );
	Code parse_variable     ( StrC var_def       );
#	endif
#	pragma endregion Parsing

#	pragma region Untyped text
	sw token_fmt_va( char* buf, uw buf_size, s32 num_tokens, va_list va );

	//! Do not use directly. Use the token_fmt macro instead.
	// Takes a format string (char const*) and a list of tokens (StrC) and returns a StrC of the formatted string.
	inline
	StrC token_fmt_impl( sw num, ... )
	{
		local_persist thread_local
		char buf[GEN_PRINTF_MAXLEN] = { 0 };
		mem_set( buf, 0, GEN_PRINTF_MAXLEN );

		va_list va;
		va_start(va, num );
		sw result = token_fmt_va(buf, GEN_PRINTF_MAXLEN, num, va);
		va_end(va);

		return { result, buf };
	}

	Code untyped_str      ( StrC content);
	Code untyped_fmt      ( char const* fmt, ... );
	Code untyped_token_fmt( char const* fmt, s32 num_tokens, ... );
#	pragma endregion Untyped text

	struct Builder
	{
		FileInfo File;
		String   Buffer;

		void print( Code );
		void print_fmt( char const* fmt, ... );

		bool open( char const* path );
		void write();
	};

#if defined(GEN_FEATURE_EDITOR) || defined(GEN_FEATURE_SCANNER)
	struct SymbolInfo
	{
		StringCached File;
		char const*  Marker;
		Code         Signature;
	};
#endif

#ifdef GEN_FEATURE_EDITOR
	struct Policy
	{
		// Nothing for now.
	};

	enum class SymbolType : u32
	{
		Code,
		Line,
		Marker
	};

	struct Editor
	{
		enum RequestType : u32
		{
			Add,
			Replace,
			Remove
		};

		struct SymbolData
		{
			Policy      Policy;
			SymbolInfo  Info;
		};

		struct RequestEntry
		{
			union {
				SymbolData Symbol;
				String     Specification;
			};
			RequestType    Type;
		};

		struct Receipt
		{
			StringCached File;
			Code         Found;
			Code         Written;
			bool         Result;
		};

		static AllocatorInfo Allocator;

		static void set_allocator( AllocatorInfo  allocator );

		Array(FileInfo)     Files;
		String              Buffer;
		Array(RequestEntry) Requests;

		void add_files( s32 num, char const** files );

		void add    ( SymbolInfo definition,  Policy policy, Code to_inject );
		void remove ( SymbolInfo definition,  Policy policy );
		void replace( SymbolInfo definition,  Policy policy, Code to_replace);

#	ifdef GEN_FEATURE_EDITOR_REFACTOR
		void refactor( char const* file_path, char const* specification_path );
#	endif

		bool process_requests( Array(Receipt) out_receipts );
	};
#endif

#ifdef GEN_FEATURE_SCANNER
	struct Scanner
	{
		struct RequestEntry
		{
			SymbolInfo Info;
		};

		struct Receipt
		{
			StringCached File;
			Code         Defintion;
			bool         Result;
		};

		AllocatorInfo MemAlloc;

		static void set_allocator( AllocatorInfo allocator );

		Array(FileInfo)     Files;
		String              Buffer;
		Array(RequestEntry) Requests;

		void add_files( s32 num, char const** files );

		void add( SymbolInfo signature, Policy policy );

		bool process_requests( Array(Receipt) out_receipts );
	};
#endif
#pragma endregion Gen Interface
}

#pragma region Macros
#	define gen_main main

#	define __ NoCode

//	Convienence for defining any name used with the gen api.
//  Lets you provide the length and string literal to the functions without the need for the DSL.
#	define name( Id_ )   { sizeof(stringize( Id_ )) - 1, stringize(Id_) }

//  Same as name just used to indicate intention of literal for code instead of names.
#	define code( ... ) { sizeof(stringize(__VA_ARGS__)) - 1, stringize( __VA_ARGS__ ) }

#	define args( ... ) macro_num_args( __VA_ARGS__ ), __VA_ARGS__

// Takes a format string (char const*) and a list of tokens (StrC) and returns a StrC of the formatted string.
#	define token_fmt( ... ) token_fmt_impl( (macro_num_args( __VA_ARGS__ ) + 1) / 2, __VA_ARGS__ )
#pragma endregion Macros

#pragma region Constants
#ifdef GEN_DEFINE_LIBRARY_CODE_CONSTANTS
namespace gen
{
	// Predefined typename codes. Are set to readonly and are setup during gen::init()

	extern Code t_b32;

	extern Code t_s8;
	extern Code t_s16;
	extern Code t_s32;
	extern Code t_s64;

	extern Code t_u8;
	extern Code t_u16;
	extern Code t_u32;
	extern Code t_u64;

	extern Code t_sw;
	extern Code t_uw;

	extern Code t_f32;
	extern Code t_f64;
}
#endif

namespace gen
{
	// These constexprs are used for allocation behavior of data structures
	// or string handling while constructing or serializing.
	// Change them to suit your needs.

	constexpr s32 InitSize_DataArrays  = 16;
	constexpr s32 InitSize_StringTable = megabytes(4);
	constexpr s32 InitSize_TypeTable   = megabytes(4);

	constexpr s32 CodePool_NumBlocks        = 4096;
	constexpr s32 InitSize_CodeEntiresArray = 512;
	constexpr s32 SizePer_CodeEntriresArena = megabytes(16);
	constexpr s32 SizePer_StringArena       = megabytes(32);

	constexpr s32 MaxCommentLineLength      = 1024;
	constexpr s32 MaxNameLength             = 128;
	constexpr s32 MaxUntypedStrLength       = kilobytes(640);
	constexpr s32 StringTable_MaxHashLength = kilobytes(1);

	// Predefined Codes. Are set to readonly and are setup during gen::init()

	extern Code t_auto;
	extern Code t_void;
	extern Code t_int;
	extern Code t_bool;
	extern Code t_char;
	extern Code t_wchar_t;
	extern Code t_class;
	extern Code t_typename;

	extern Code access_public;
	extern Code access_protected;
	extern Code access_private;

	extern Code module_global_fragment;
	extern Code module_private_fragment;

	extern Code pragma_once;

	extern Code spec_const;
	extern Code spec_consteval;
	extern Code spec_constexpr;
	extern Code spec_constinit;
	extern Code spec_extern_linkage;
	extern Code spec_global;
	extern Code spec_inline;
	extern Code spec_internal_linkage;
	extern Code spec_local_persist;
	extern Code spec_mutable;
	extern Code spec_ptr;
	extern Code spec_ref;
	extern Code spec_register;
	extern Code spec_rvalue;
	extern Code spec_static_member;
	extern Code spec_thread_local;
	extern Code spec_volatile;
}
#pragma endregion Constants

#pragma region Inlines
namespace gen
{
	inline
	void AST::add_entry( AST* other )
	{
		AST* to_add = other->Parent ?
			other->duplicate() : other;

		if (DynamicEntries)
			ArrDyn.append( to_add );

		else
		{
			if ( StaticIndex < ArrS_Cap )
			{
				ArrStatic[StaticIndex] = to_add;
				StaticIndex++;
			}
			else
			{
				ArrDyn = make_code_entries();

				s32 index = 0;
				do
				{
					ArrDyn.append( ArrStatic[index] );
				}
				while ( StaticIndex--, StaticIndex );

				ArrDyn.append( to_add );
			}
		}

		to_add->Parent = this;
	}
}
#pragma endregion Inlines

// end: gen_time
#endif