Instantiation via the command line

Another way of manually controlling instantiation is via the -T option to CC. The suboptions you can use to do this are:

• none - do not do any instantiation.

• used - instantiate those template entities used in the compilation. This includes all static data members for which there are definitions.

• all - instantiate all template entities declared or referenced in the compilation unit. For each instantiated template class, this includes all its member functions and static data members, whether or not they are used. Non-member function templates will be instantiated even if the only reference was a declaration.

• local - like used except that all the instantiated functions are given internal linkage. This will prevent name collisions between object files, at the expense of possibly generating many copies of instantiated functions across a set of source files, which may make this option unsuitable for production use.

These options to CC might typically be used with dummy source files that include the headers that describe the templates and their argument types and that make dummy references to the template classes used by the rest of the application. These source files would be compiled using the various options mentioned above and the resulting objects linked with the application.