solidity/libsolutil/cxx20.h
2021-07-15 15:24:12 +02:00

64 lines
2.1 KiB
C++

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
// SPDX-License-Identifier: GPL-3.0
#include <map>
// Contains polyfills of STL functions and algorithms that will become available in C++20.
namespace solidity::cxx20
{
// Taken from https://en.cppreference.com/w/cpp/container/map/erase_if.
template<class Key, class T, class Compare, class Alloc, class Pred>
typename std::map<Key, T, Compare, Alloc>::size_type erase_if(std::map<Key,T,Compare,Alloc>& _c, Pred _pred)
{
auto old_size = _c.size();
for (auto i = _c.begin(), last = _c.end(); i != last;)
if (_pred(*i))
i = _c.erase(i);
else
++i;
return old_size - _c.size();
}
// Taken from https://en.cppreference.com/w/cpp/container/unordered_map/erase_if.
template<class Key, class T, class Hash, class KeyEqual, class Alloc, class Pred>
typename std::unordered_map<Key, T, Hash, KeyEqual, Alloc>::size_type
erase_if(std::unordered_map<Key, T, Hash, KeyEqual, Alloc>& _c, Pred _pred)
{
auto old_size = _c.size();
for (auto i = _c.begin(), last = _c.end(); i != last;)
if (_pred(*i))
i = _c.erase(i);
else
++i;
return old_size - _c.size();
}
// Taken from https://en.cppreference.com/w/cpp/container/vector/erase2
template<class T, class Alloc, class Pred>
constexpr typename std::vector<T, Alloc>::size_type
erase_if(std::vector<T, Alloc>& c, Pred pred)
{
auto it = std::remove_if(c.begin(), c.end(), pred);
auto r = std::distance(it, c.end());
c.erase(it, c.end());
return static_cast<typename std::vector<T, Alloc>::size_type>(r);
}
}