defines_ostream_operator.h

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#pragma once

#include <type_traits>
#include <iostream>
#include <string>
#include <scl/tools/meta/void_t.h>
#include <scl/tools/meta/exists.h>
#include <scl/tools/meta/enable_if.h>
#include <scl/tools/meta/type_mod.h>

namespace scl{
    namespace tools{
        namespace meta{
            namespace details{
                template <class T, class = void>
                struct __ostream_op_defined : std::false_type{};

                template <class T>
                struct __ostream_op_defined<T, /*enable_if_t*/void_t<
                                                              /*exists<*/decltype(operator<<(std::declval<std::ostream&>(), std::declval<const T&>()))/*>()*/
                >> : std::true_type{};
            }

            template <class T>
            inline constexpr bool defines_ostream_operator(){
                return details::__ostream_op_defined<decay_t<T>>::value;
            }
        }
    }
}