iif.h

/*  This file is part of the Vc library. {{{
Copyright © 2012-2015 Matthias Kretz <kretz@kde.org>
All rights reserved.

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}}}*/

#ifndef VC_COMMON_IIF_H_
#define VC_COMMON_IIF_H_

#include <Vc/type_traits>
#include "macros.h"

namespace Vc_VERSIONED_NAMESPACE
{

namespace
{
    template<typename T> struct assert_for_iif
    {
        typedef T type;
        static_assert(Vc::is_simd_vector<T>::value, "Incorrect use of Vc::iif. If you use a mask as first parameter, the second and third parameters must be of vector type.");
    };
} // anonymous namespace

template<typename Mask, typename T> Vc_ALWAYS_INLINE
typename std::enable_if<Vc::is_simd_mask<Mask>::value, typename assert_for_iif<T>::type>::type
iif(const Mask &condition, const T &trueValue, const T &falseValue)
{
    T result(falseValue);
    Vc::where(condition) | result = trueValue;
    return result;
}

/* the following might be a nice shortcut in some cases, but:
 * 1. it fails if there are different vector classes for the same T
 * 2. the semantics are a bit fishy: basically the mask determines how to blow up the scalar values
template<typename Mask, typename T> Vc_ALWAYS_INLINE
typename std::enable_if<Vc::is_simd_mask<Mask>::value && !Vc::is_simd_vector<T>::value, void>::type
#ifndef Vc_MSVC
iif(Mask condition, T trueValue, T falseValue)
#else
iif(const Mask &condition, T trueValue, T falseValue)
#endif
{
    Vc::Vector<T> f = falseValue;
    Vc::where(condition) | f = trueValue;
    return f;
}
 */

template<typename T> constexpr T iif (bool condition, const T &trueValue, const T &falseValue)
{
    return condition ? trueValue : falseValue;
}

}  // namespace Vc

#endif // VC_COMMON_IIF_H_