anki-3d-engine/include/anki/util/ConstCharPtrHashMap.h

#ifndef ANKI_UTIL_CONST_CHAR_PTR_HASH_MAP_H
#define ANKI_UTIL_CONST_CHAR_PTR_HASH_MAP_H

#include <unordered_map>
#include <cstring>

namespace anki {

/// The hash function
struct CreateCharPtrHashMapKey
{
	size_t operator()(const char* str) const
	{
		size_t h = 0;
		for (; *str != '\0'; ++str)
		{
			h += *str;
		}
		return h;
	}
};

/// The collision evaluation function
struct CompareCharPtrHashMapKeys
{
	bool operator()(const char* a, const char* b) const
	{
		return strcmp(a, b) == 0;
	}
};

/// The hash map that has as key an old school C string. When inserting the
/// char MUST NOT point to a temporary or the evaluation function will fail.
/// Its template struct because C++ does not offer template typedefs
template<typename T>
struct ConstCharPtrHashMap
{
	typedef std::unordered_map<const char*, T,
		CreateCharPtrHashMapKey, CompareCharPtrHashMapKeys> Type;
};

} // end namespace

#endif