simple example + template<> example
+"Fix-it" hints provide advice for fixing small, localized problems +in source code. When Clang produces a diagnostic about a particular +problem that it can work around (e.g., non-standard or redundant +syntax, missing keywords, common mistakes, etc.), it may also provide +specific guidance in the form of a code transformation to correct the +problem. For example, here Clang warns about the use of a GCC +extension that has been considered obsolete since 1993:
+
+ $ clang t.c
+ t.c:5:28: warning: use of GNU old-style field designator extension
+ struct point origin = { x: 0.0, y: 0.0 };
+ ~~ ^
+ .x =
+ t.c:5:36: warning: use of GNU old-style field designator extension
+ struct point origin = { x: 0.0, y: 0.0 };
+ ~~ ^
+ .y =
+
+
+The underlined code should be removed, then replaced with the code below the caret line (".x =" or ".y =", respectively). "Fix-it" hints are most useful for working around common user errors and misconceptions. For example, C++ users commonly forget the syntax for explicit specialization of class templates, as in the following error:
+ +
+ $ clang t.cpp
+ t.cpp:9:3: error: template specialization requires 'template<>'
+ struct iterator_traits<file_iterator> {
+ ^
+ template<>
+
+
+Again, after describing the problem, Clang provides the fix--add template<>--as part of the diagnostic.