unique_ptr and make_unique

configure.ac

@@ -130,6 +130,9 @@ AC_C_BIGENDIAN
 # Nice to have when an assertion triggers
 LYX_CHECK_CALLSTACK_PRINTING
 
+# C++14 only
+LYX_CHECK_DEF(make_unique, memory, [using std::make_unique;])
+
 # Needed for our char_type
 AC_CHECK_SIZEOF(wchar_t)
 

src/support/Makefile.am

@@ -106,6 +106,7 @@ liblyxsupport_a_SOURCES = \
 	trivstring.cpp \
 	trivstring.h \
 	types.h \
+	unique_ptr.h \
 	userinfo.cpp \
 	userinfo.h \
 	unicode.cpp \

src/support/unique_ptr.h

@@ -0,0 +1,74 @@
+// -*- C++ -*-
+/**
+ * \file unique_ptr.h
+ * This file is part of LyX, the document processor.
+ * Licence details can be found in the file COPYING.
+ *
+ * \author Guillaume Munch
+ *
+ * Full author contact details are available in file CREDITS.
+ */
+
+#ifndef LYX_UNIQUE_PTR_H
+#define LYX_UNIQUE_PTR_H
+
+#include <memory>
+
+namespace lyx { using std::unique_ptr; }
+
+
+/// Define lyx::make_unique() across platforms
+
+#ifdef HAVE_DEF_MAKE_UNIQUE
+
+namespace lyx { using std::make_unique; }
+
+#else
+// For all other compilers:
+// using https://isocpp.org/files/papers/N3656.txt
+
+#include <cstddef>
+#include <type_traits>
+#include <utility>
+
+
+namespace lyx {
+
+namespace {
+
+template<class T> struct _Unique_if {
+	typedef unique_ptr<T> _Single_object;
+};
+
+template<class T> struct _Unique_if<T[]> {
+	typedef unique_ptr<T[]> _Unknown_bound;
+};
+
+template<class T, size_t N> struct _Unique_if<T[N]> {
+	typedef void _Known_bound;
+};
+
+} //anon namespace
+
+template<class T, class... Args>
+typename _Unique_if<T>::_Single_object
+make_unique(Args&&... args) {
+	return unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+
+template<class T>
+typename _Unique_if<T>::_Unknown_bound
+make_unique(size_t n) {
+	typedef typename std::remove_extent<T>::type U;
+	return unique_ptr<T>(new U[n]());
+}
+
+template<class T, class... Args>
+typename _Unique_if<T>::_Known_bound
+make_unique(Args&&...) = delete;
+
+} // namespace lyx
+
+#endif // definition of make_unique
+
+#endif // LYX_UNIQUE_PTR_H