Template Definition Searching

When you use the definitions-separate template organization, template definitions are not available in the current compilation unit, and the compiler must search for the definition. This section describes how the compiler locates the definition.

Definition searching is somewhat complex and prone to error. Therefore, you should use the definitions-included template file organization if possible. Doing so helps you avoid definition searching altogether. See the C++ Programming Guide.

Source File Location Conventions

Without the specific directions provided with an options file, the compiler uses a Cfront-style method to locate template definition files. This method requires that the template definition file contain the same base name as the template declaration file. This method also requires that the template definition file be on the current include path. For example, if the template function foo() is located in foo.h, the matching template definition file should be named foo.cc or some other recognizable source-file extension (.C, .c, .cc, .cpp, or .cxx). The template definition file must be located in one of the normal include directories or in the same directory as its matching header file.

Definitions Search Path

As an alternative to the normal search path set with -I, you can specify a search directory for template definition files with the option -ptidirectory. Multiple -pti flags define multiple search directories--that is, a search path. If you use -ptidirectory, the compiler looks for template definition files on this path and ignores the -I flag. Since the -ptidirectory flag complicates the search rules for source files, use the -I option instead of the -ptidirectory option.