X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=src%2Fsupport%2Flyxalgo.h;h=7f4fda7281f9c23cd8cd7449e0a3fc7228c3ec7a;hb=5e7275dabc36e1acb396c45ba27aecf8d8a0171e;hp=79799011060d5443ed897867fda58e5b3d7eeae0;hpb=fa492d6bf09db7f1c278687e0000ad1c4833af3d;p=lyx.git

diff --git a/src/support/lyxalgo.h b/src/support/lyxalgo.h
index 7979901106..7f4fda7281 100644
--- a/src/support/lyxalgo.h
+++ b/src/support/lyxalgo.h
@@ -1,12 +1,23 @@
 // -*- C++ -*-
+/**
+ * \file lyxalgo.h
+ * Copyright 1995-2002 the LyX Team
+ * Read the file COPYING
+ *
+ * A variety of useful templates.
+ *
+ * \author unknown
+ */
 
 #ifndef LYX_ALGO_H
 #define LYX_ALGO_H
 
-// Both these functions should ideally be placed into namespace lyx.
-// Also the using std::less should not be used.
+#include <utility>
+#include <iterator>
+#include <algorithm>
+
+namespace lyx {
 
-//namespace lyx {
 
 /// Returns true if the sequence first,last is sorted, false if not.
 template <class For>
@@ -20,6 +31,7 @@ bool sorted(For first, For last)
 	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)
@@ -32,5 +44,56 @@ bool sorted(For first, For last, Cmp cmp)
 	return true;
 }
 
-// }  // end of namespace lyx
+
+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;
+}
+
+
+/// A slot in replacement for std::count for systems where it is broken.
+template <class Iterator, class T>
+typename std::iterator_traits<Iterator>::difference_type
+count (Iterator first, Iterator last, T const & value)
+{
+#ifdef HAVE_STD_COUNT
+	return std::count(first, last, value);
+#else
+	std::iterator_traits<Iterator>::difference_type n = 0;
+	while (first != last)
+		if (*first++ == value) ++n;
+	return n;
 #endif
+}
+
+/// Remove all duplicate entries in c.
+template<class C>
+void eliminate_duplicates(C & c)
+{
+	std::sort(c.begin(), c.end());
+	typename C::iterator p = std::unique(c.begin(), c.end());
+	c.erase(p, c.end());
+}
+
+} // namespace lyx
+
+#endif // LYX_ALGO_H