lyx_mirror/src/support/lyxalgo.h
Jean-Marc Lasgouttes 329eae5605 Use explicit macro to declare that we want to use C++11
This replaces tests for __cplusplus >= 201103L, which are wrong with gcc 4.6 and earlier. Indeed these versions of gcc define __cplusplus = 1.

Reference:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=1773
2015-05-20 10:19:19 +02:00

115 lines
2.1 KiB
C++

// -*- C++ -*-
/**
* \file lyxalgo.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Lars Gullik Bjønnes
*
* Full author contact details are available in file CREDITS.
*
* A variety of useful templates.
*/
#ifndef LYX_ALGO_H
#define LYX_ALGO_H
#include <utility>
#include <iterator>
#include <algorithm>
namespace lyx {
/// Returns true if the sequence first,last is sorted, false if not.
template <class For>
bool sorted(For first, For last)
{
if (first == last) return true;
For tmp = first;
while (++tmp != last) {
if (*tmp < *first++) return false;
}
return true;
}
/// Cmp is the same Cmp as you would pass to std::sort.
template <class For, class Cmp>
bool sorted(For first, For last, Cmp cmp)
{
if (first == last) return true;
For tmp = first;
while (++tmp != last) {
if (cmp(*tmp, *first++)) return false;
}
return true;
}
struct firster {
template <class P1, class P2>
P1 operator()(std::pair<P1, P2> const & p) {
return p.first;
}
};
/**
* copy elements in the given range to the output iterator
* if the predicate evaluates as true
*/
template <class InputIter, class OutputIter, class Func>
OutputIter copy_if(InputIter first, InputIter last,
OutputIter result, Func func)
{
for (; first != last; ++first) {
if (func(*first)) {
*result++ = *first;
}
}
return result;
}
/// Remove all duplicate entries in c.
template<class C>
void eliminate_duplicates(C & c)
{
// It is a requirement that the container is sorted for
// std::unique to work properly.
std::sort(c.begin(), c.end());
c.erase(std::unique(c.begin(), c.end()), c.end());
}
#ifdef LYX_USE_CXX11
using std::next;
#else
/// Replacement of std::next for older compilers
template <typename It, typename Diff>
inline It next(It i, Diff n = 1)
{
std::advance(i, n);
return i;
}
#endif
#ifdef LYX_USE_CXX11
using std::prev;
#else
/// Replacement of std::prev for older compilers
template <typename It, typename Diff>
inline It prev(It i, Diff n = 1)
{
std::advance(i, -n);
return i;
}
#endif
} // namespace lyx
#endif // LYX_ALGO_H