70 lines
1.9 KiB
C++
70 lines
1.9 KiB
C++
/*
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
*
|
|
* Copyright 2012-2017 Danny Robson <danny@nerdcruft.net>
|
|
*/
|
|
|
|
#ifndef UTIL_TYPES_COMPARATOR_HPP
|
|
#define UTIL_TYPES_COMPARATOR_HPP
|
|
|
|
#include <memory>
|
|
|
|
#include "../iterator/zip.hpp"
|
|
|
|
namespace cruft::comparator {
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// Compares standard types that can be reduced to pointers.
|
|
template <typename T>
|
|
struct pointer {
|
|
constexpr
|
|
bool
|
|
operator() (const std::unique_ptr<T> &a, const std::unique_ptr<T> &b)
|
|
{
|
|
return a < b;
|
|
}
|
|
|
|
constexpr
|
|
bool
|
|
operator() (const T *a, const std::unique_ptr<T> &b)
|
|
{
|
|
return a < b.get ();
|
|
}
|
|
|
|
constexpr
|
|
bool
|
|
operator() (const std::unique_ptr<T> &a, const T *b)
|
|
{
|
|
return a.get () < b;
|
|
}
|
|
};
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// Provides a comparison interface for types exposing an index operator.
|
|
///
|
|
/// Will return true if the first parameter has the first index that
|
|
/// compares less than the second parameter. Useful for providing a total
|
|
/// order of coordinate types where this doesn't make sense by default.
|
|
///
|
|
/// \tparam T The container data type to compare. Must provide an index
|
|
/// operator.
|
|
template <typename T>
|
|
struct indexed {
|
|
constexpr
|
|
bool operator() (const T &a, const T &b) const
|
|
{
|
|
for (auto x: cruft::iterator::zip (a, b)) {
|
|
const auto &[i,j] = x; // BUG: clang-4.0: workaround for segfault.
|
|
if (i < j) return true;
|
|
if (i != j) return false;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
};
|
|
}
|
|
|
|
#endif
|