Manually merged PR 145 for C.150 improvement

CppCoreGuidelines.md

@@ -5873,6 +5873,7 @@ Avoid resource leaks.
 ##### Reason
 
  `make_unique` gives a more concise statement of the construction.
+It also ensures exception safety in complex expressions.
 
 ##### Example
 
@@ -5880,6 +5881,19 @@ Avoid resource leaks.
 
     auto q = make_unique<Foo>(7);		// Better: no repetition of Foo
 
+    // Not exception-safe: the compiler may interleave the computations of arguments as follows:
+    //
+    // 1. allocate memory for Foo,
+    // 2. construct Foo,
+    // 3. call bar,
+    // 4. construct unique_ptr<Foo>.
+    //
+    // If bar throws, Foo will not be destroyed, and the memory allocated for it will leak.
+    f(unique_ptr<Foo>(new Foo()), bar());
+
+    // Exception-safe: calls to functions are never interleaved.
+    f(make_unique<Foo>(), bar());
+
 ##### Enforcement
 
 * Flag the repetitive usage of template specialization list `<Foo>`