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invoke_function_object
Description

Calls a Polymorphic Function Object with the arguments from a Sequence.

The first template parameter can be specialized explicitly to avoid copying and/or to control the const qualification of a function object.

Synopsis
template<
    typename Function,
    class Sequence
    >
typename result_of::invoke_function_object<Function, Sequence>::type
invoke_function_object(Function f, Sequence & s);

template<
    typename Function,
    class Sequence
    >
typename result_of::invoke_function_object<Function, Sequence const>::type
invoke_function_object(Function f, Sequence const & s);
Parameters

Parameter

Requirement

Description

f

Model of Polymorphic Function Object

The function object to call.

s

Model of Forward Sequence

The arguments.

Expression Semantics
invoke_function_object(f,s);

Return type: Return type of f when invoked with the elements in s as its arguments.

Semantics: Invokes f with the elements in s as arguments and returns the result of the call expression.

/functional/invocation/invoke_function_object.hpp>

Example
struct sub
{
    template <typename Sig>
    struct result;

    template <class Self, typename T>
    struct result< Self(T,T) >
    { typedef typename remove_reference<T>::type type; };

    template<typename T>
    T operator()(T lhs, T rhs) const
    {
        return lhs - rhs;
    }
};

void try_it()
{
    sub f;
    assert(f(2,1) == invoke_function_object(f,make_vector(2,1)));
}
See also

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