Implement result_of for the new ternary functors

This commit is contained in:
Benoit Steiner 2016-06-06 12:06:42 -07:00
parent df24f4a01d
commit 33f0340188

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@ -328,6 +328,30 @@ struct result_of<Func(ArgType0,ArgType1)> {
enum {FunctorType = sizeof(testFunctor(static_cast<Func*>(0)))};
typedef typename binary_result_of_select<Func, ArgType0, ArgType1, FunctorType>::type type;
};
template<typename Func, typename ArgType0, typename ArgType1, typename ArgType2, int SizeOf=sizeof(has_none)>
struct ternary_result_of_select {typedef typename internal::remove_all<ArgType0>::type type;};
template<typename Func, typename ArgType0, typename ArgType1, typename ArgType2>
struct ternary_result_of_select<Func, ArgType0, ArgType1, ArgType2, sizeof(has_std_result_type)>
{typedef typename Func::result_type type;};
template<typename Func, typename ArgType0, typename ArgType1, typename ArgType2>
struct ternary_result_of_select<Func, ArgType0, ArgType1, ArgType2, sizeof(has_tr1_result)>
{typedef typename Func::template result<Func(ArgType0,ArgType1,ArgType2)>::type type;};
template<typename Func, typename ArgType0, typename ArgType1, typename ArgType2>
struct result_of<Func(ArgType0,ArgType1,ArgType2)> {
template<typename T>
static has_std_result_type testFunctor(T const *, typename T::result_type const * = 0);
template<typename T>
static has_tr1_result testFunctor(T const *, typename T::template result<T(ArgType0,ArgType1,ArgType2)>::type const * = 0);
static has_none testFunctor(...);
// note that the following indirection is needed for gcc-3.3
enum {FunctorType = sizeof(testFunctor(static_cast<Func*>(0)))};
typedef typename ternary_result_of_select<Func, ArgType0, ArgType1, ArgType2, FunctorType>::type type;
};
#endif
/** \internal In short, it computes int(sqrt(\a Y)) with \a Y an integer.