gplib/include/gp_config.hpp

#pragma once
#include <cstdint>
#include <cstddef>
#include <cstdlib>
#include <type_traits>

namespace gp_config{
	namespace memory_module{
		enum class memory_mode_t{
			other,
			clib,
			buffer,
			arena_buffer
		};

		constexpr memory_mode_t memory_mode = memory_mode_t::clib;


		template<memory_mode_t T = memory_mode_t::other>
		constexpr void*(*memory_allocator)(std::size_t)=nullptr;
		template<memory_mode_t T = memory_mode_t::other>
		constexpr void(*memory_deallocator)(void*)=nullptr;

		// C Standard library memory usage
		template<>
		constexpr void*(*memory_allocator<memory_mode_t::clib>)(std::size_t) = malloc;
		template<>
		constexpr void(*memory_deallocator<memory_mode_t::clib>)(void*) = free;

		// Buffer memory usage only
		template<>
		constexpr void*(*memory_allocator<memory_mode_t::buffer>)(std::size_t) = nullptr;
		template<>
		constexpr void(*memory_deallocator<memory_mode_t::buffer>)(void*) = nullptr;

		// Buffer of arena memory usage
		template<>
		constexpr void*(*memory_allocator<memory_mode_t::arena_buffer>)(std::size_t) = nullptr;
		template<>
		constexpr void(*memory_deallocator<memory_mode_t::arena_buffer>)(void*) = nullptr;

		constexpr bool is_ok = 
			( memory_allocator<memory_mode> != nullptr )
			&& ( memory_deallocator<memory_mode> != nullptr );
	}

	constexpr bool has_exceptions = true;
	constexpr bool has_buffer_bounds = true;

	// Value of  8 is considered not cryptographically secure
	// Value of 12 offers a good compromise of performance and robustness
	// Value of 20 offers maximum robustness
	constexpr size_t arc4random_strength = 20;

	struct assert_failure{
		assert_failure(const char* reason)
		: what_str{reason}
		{}
		const char* what_str;
		const char* what() {return what_str;}
	};

	constexpr size_t assert_buffer_size = 0;
	constexpr auto assertion = [](bool pred, const char* reason) -> void{
		if constexpr (has_exceptions)
		if(!pred) throw assert_failure(reason);
	};
}

enum class gp_errorcodes : int {
	infinite_skipstone = 3000
};