Boost.Hana: boost::hana::detail::wrong<... > Struct Template Reference

| Boost.Hana 1.0.0 Your standard library for metaprogramming |

boost::hana::detail::wrong<... > Struct Template Reference

## Description

### template<typename...>
struct boost::hana::detail::wrong<... >

Equivalent to a type-dependent `std::false_type`.

This is useful for making a static assertion that would otherwise always fire up dependent on some template parameters.

## Example

// Copyright Louis Dionne 2013-2016
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#include <boost/hana/detail/wrong.hpp>
namespace hana = boost::hana;
template <typename T, typename U>
struct base_template {
// Can't write this because the assertion would always fire up:
// static_assert(false, "...");
// So instead we write this:
static_assert(hana::detail::wrong<base_template<T, U>>{},
"base_template does not have a valid default definition");
};
template <>
struct base_template<int, int> {
// something useful
};
int main() { }

Inherits false_type.