HasAssign.h

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/*
 * Copyright (C) 2012 by
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 * and
 *   Neuroinformatics and Cognitive Robotics Labs (NICR) at TU Ilmenau, GERMANY
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#ifndef _MIRA_HASASSIGN_H_
#define _MIRA_HASASSIGN_H_

#include <type_traits>

namespace mira {


namespace detail {

template <typename T, typename U>
class HasAssignHelper
{
private:
    struct Failure {};

    template <typename V>
    static V value() {}

    template <typename V>
    static auto testassign(T x, V y) -> decltype(x = y);
    static Failure testassign(...);

public:
    typedef decltype(testassign(value<T>(), value<U>())) AssignResultType;

    typedef std::is_same<AssignResultType,Failure> not_type;
};

}


template <typename T, typename U>
class has_assign :
    public std::integral_constant<bool, !detail::HasAssignHelper<T,U>::not_type::value>
{};


} // namespace

#endif