Fix bugs #6078 and #9364

[lyx.git] / src / support / lyxalgo.h

diff --git a/src/support/lyxalgo.h b/src/support/lyxalgo.h
index 2d8d49f06c943b3bf615987e90238e8a987803e2..9e44838a795233bf70df36686f3d9eacea068d1a 100644 (file)
--- a/src/support/lyxalgo.h
+++ b/src/support/lyxalgo.h
@@ -1,9 +1,23 @@
 // -*- 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 {
 
@@ -42,9 +56,13 @@ struct firster {
 };
 
 
+/**
+ * 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) 
+              OutputIter result, Func func)
 {
        for (; first != last; ++first) {
                if (func(*first)) {
@@ -54,5 +72,43 @@ OutputIter copy_if(InputIter first, InputIter last,
        return result;
 }
 
-}  // end of namespace lyx
+
+/// 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