ugmisc::call_foo_method< T > Struct Template Reference

#include <ugmisc/member.hpp>

Public Types
template<class... U>
using	matched_type = ???

Public Member Functions
template<class... U>
constexpr decltype(auto)	operator() (U &&...) const

Static Public Member Functions
template<class... U>
static constexpr decltype(auto)	call (U &&...args)
template<class F>
static constexpr auto	fallback (F &&functor)
template<class... U>
static constexpr bool	is_matched (U &&...)
template<class... U>
static matched_type< U... >	declval_matched (U &&...) noexcept

Static Public Attributes
template<class... U>
static constexpr bool	is_matched_v = ???

Detailed Description

template<class... T>
struct ugmisc::call_foo_method< T >

This is an example of the type of template that is created by the UGMISC_NAMED_MEMBER_STATIC_METHOD_CALL and UGMISC_MEMBER_STATIC_METHOD_CALL macros.

In this example the NAME parameter of the macro is foo.

Member Typedef Documentation

matched_type

template<class... T>

template<class... U>

using ugmisc::call_foo_method< T >::matched_type = ???

This is the type whose foo method would be called if the given parameter types were passed. If there is no suitable type then use of matched_type will not be valid.

Member Function Documentation

call()

template<class... T>

template<class... U>

constexpr decltype(auto) ugmisc::call_foo_method< T >::call ( U &&... args )

staticconstexpr

Forwards args to the first T::foo static method that can be called with those parameter types, and returns the result. If no such method exists, the call is a compile time error.

declval_matched()

template<class... T>

template<class... U>

matched_type< U... > ugmisc::call_foo_method< T >::declval_matched ( U && ... )

staticnoexcept

This declaration has no matching definition. It can be used where you would use std::declval<>(). It is an expression of the same type as the type whose static method would be called if arguments of type U... were passed to call.

fallback()

template<class... T>

template<class F>

constexpr auto ugmisc::call_foo_method< T >::fallback ( F && functor )

staticconstexpr

Provides a fallback default value getter. This is a callable rather than the default value, so that default values which have a runtime overhead to create and destroy can be avoided where they are not needed.

The callable may accept the forwarded arguments that were supposed to be passed to a static foo() method of one of the T type parameters, or it may accept no arguments. For example:

call_foo_method<X, Y, Z>::fallback(default_foo)(args...);

This will make the first valid call and return the results:

• X::foo(args...)
• Y::foo(args...)
• Z::foo(args...)
• default_foo(args...)
• default_foo()

Returns

An object which is callable just like an instance of call_foo_method is callable, but will fall back to calling the provided function or functor if the type parameters don't support the method call.

Parameters

functor

Creates a default return value if needed.

is_matched()

template<class... T>

template<class... U>

constexpr bool ugmisc::call_foo_method< T >::is_matched ( U && ... )

staticconstexpr

See also

is_matched_v

operator()()

template<class... T>

template<class... U>

decltype(auto) ugmisc::call_foo_method< T >::operator() ( U && ... ) const

constexpr

Forwards its arguments to the static method call_foo_method::call. So the following two statements are effectively the same:

call_foo_method<X, Y, Z>::call(1, 2);
call_foo_method<X, Y, Z>{}(1, 2);

Member Data Documentation

is_matched_v

template<class... T>

template<class... U>

bool ugmisc::call_foo_method< T >::is_matched_v = ???

staticconstexpr

True if a call with the given parameter types is valid.

Template Parameters

U	The function call parameter types.

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The documentation for this struct was generated from the following file:

• ugmisc/member.hpp