is_implicit_cast_allowed.h

/*  This file is part of the Vc library. {{{
Copyright © 2015 Matthias Kretz <kretz@kde.org>

Redistribution and use in source and binary forms, with or without
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    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
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      documentation and/or other materials provided with the distribution.
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      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

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ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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}}}*/

#ifndef VC_TRAITS_IS_IMPLICIT_CAST_ALLOWED_H_
#define VC_TRAITS_IS_IMPLICIT_CAST_ALLOWED_H_

namespace Vc_VERSIONED_NAMESPACE
{
namespace Traits
{
template <typename From, typename To, bool = std::is_integral<From>::value>
struct is_implicit_cast_allowed
    : public std::integral_constant<
          bool, std::is_same<From, To>::value ||
                    (std::is_integral<To>::value &&
                     (std::is_same<typename std::make_unsigned<From>::type, To>::value ||
                      std::is_same<typename std::make_signed<From>::type, To>::value))> {
};

template <typename From, typename To>
struct is_implicit_cast_allowed<From, To, false> : public std::is_same<From, To>::type {
};

template <typename From, typename To>
struct is_implicit_cast_allowed_mask : public is_implicit_cast_allowed<From, To> {
};

static_assert(is_implicit_cast_allowed<float, float>::value, "");
static_assert(!is_implicit_cast_allowed<float, double>::value, "");
static_assert(is_implicit_cast_allowed< int64_t, uint64_t>::value, "");
static_assert(is_implicit_cast_allowed<uint64_t,  int64_t>::value, "");
static_assert(is_implicit_cast_allowed< int32_t, uint32_t>::value, "");
static_assert(is_implicit_cast_allowed<uint32_t,  int32_t>::value, "");
static_assert(is_implicit_cast_allowed< int16_t, uint16_t>::value, "");
static_assert(is_implicit_cast_allowed<uint16_t,  int16_t>::value, "");
static_assert(is_implicit_cast_allowed<  int8_t,  uint8_t>::value, "");
static_assert(is_implicit_cast_allowed< uint8_t,   int8_t>::value, "");

}  // namespace Traits
}  // namespace Vc

#endif  // VC_TRAITS_IS_IMPLICIT_CAST_ALLOWED_H_

// vim: foldmethod=marker