Hash-util

Helper macros for specializing the std::hash. More...

Classes
struct	eu::core::HashCombiner
	A utility for combining hash values of multiple objects into a single hash value. More...

Macros
#define	HASH_DEF_BEGIN(TYPE)
	Begins the definition of a specialization of std::hash for the given TYPE.
#define	HASH_DEF(NAME)   .combine(x.NAME)
	Adds the hash of a member variable to the hash combination.
#define	HASH_DEF_END()
	Ends the definition of the std::hash specialization.

Detailed Description

Helper macros for specializing the std::hash.

This group provides a util HashCombiner to simplify the creation of hash functions for user-defined types (using std::hash) and macros for specialization of std::hash for custom types.

Example usage:

HASH_DEF_BEGIN(MyType)
    HASH_DEF(member1)
    HASH_DEF(member2)
HASH_DEF_END()

Macro Definition Documentation

HASH_DEF

#define HASH_DEF

(

NAME

)

.combine(x.NAME)

#include <libs/core/src/eu/core/hash.h>

Adds the hash of a member variable to the hash combination.

\hideinlinesource

This macro should be used within a HASH_DEF_BEGIN and HASH_DEF_END block to combine the hash of a specific member variable of the type.

Parameters

NAME	The name of the member variable to include in the hash.

Definition at line 70 of file hash.h.

HASH_DEF_BEGIN

#define HASH_DEF_BEGIN

(

TYPE

)

#include <libs/core/src/eu/core/hash.h>

Value:

    template<> \
    struct std::hash<TYPE> \
    { \
        std::size_t operator()(const TYPE& x) const \
        { \
            return eu::core::HashCombiner \
            { \
            }

Begins the definition of a specialization of std::hash for the given TYPE.

Should be closed by the HASH_DEF_END macro

Parameters

TYPE	The user-defined type for which the hash specialization is being created. \hideinlinesource

Definition at line 51 of file hash.h.

HASH_DEF_END

#define HASH_DEF_END

(

)

#include <libs/core/src/eu/core/hash.h>

Value:

    .result; \
    } \
    } \
    ;

Ends the definition of the std::hash specialization.

This macro should be used to close the hash function definition started with HASH_DEF_BEGIN. It returns the final combined hash value.

\hideinlinesource

Definition at line 79 of file hash.h.