File size: 1,540 Bytes
8ae5fc5 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | #ifndef METAL_VALUE_SAME_HPP
#define METAL_VALUE_SAME_HPP
#include "../config.hpp"
namespace metal {
/// \cond
namespace detail {
template <class... vals>
struct _same;
}
/// \endcond
/// \ingroup value
///
/// ### Description
/// Checks whether all \values are identical.
///
/// ### Usage
/// For any \values `val_0, ..., val_n-1`
/// \code
/// using result = metal::same<val_0, ..., val_n-1>;
/// \endcode
///
/// \returns: \number
/// \semantics:
/// If at least two \values in `val_0, ..., val_n-1` are not identical
/// to each other, then
/// \code
/// using result = metal::false_;
/// \endcode
/// otherwise
/// \code
/// using result = metal::true_;
/// \endcode
///
/// ### Example
/// \snippet value.cpp same
///
/// ### See Also
/// \see distinct
template <class... vals>
using same = typename detail::_same<vals...>::type;
}
#include "../number/number.hpp"
#include "../value/value.hpp"
namespace metal {
/// \cond
namespace detail {
template <class...>
struct _same_impl : false_ {
};
template <template <class> class... _, class val>
struct _same_impl<_<val>...> : true_ {
};
template <class... vals>
struct _same : _same_impl<maybe<vals>...> {
};
template <class x, class y>
struct _same<x, y> : false_ {
};
template <class x>
struct _same<x, x> : true_ {
};
template <class x>
struct _same<x> : true_ {
};
template <>
struct _same<> : true_ {
};
}
/// \endcond
}
#endif
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