Static Instances

With the static instances method, all instances are placed within the current compilation unit. As a consequence, templates are reinstantiated during each recompilation; instances are not saved to the template repository.

Instances receive static linkage. These instances will not be visible or usable outside the current compilation unit. As a result, templates might have identical instantiations in several object files. This has the following undesirable consequences:

• Multiple instances produce unnecessarily large programs. (Static instance linkage is therefore suitable only for small programs, where templates are unlikely to be multiply instantiated.)

• Templates that contain static variables have many copies of the variable, and this is an unavoidable violation of the C++ standard. Therefore, use of static instances is not supported with static variables within templates.

Compilation is potentially faster with static instances, so this method might also be suitable during Fix-and-Continue debugging. (See Debugging a Program With dbx.)

Specify static instance linkage with the -instances=static compiler option. You can use static instance linkage only with the definitions-included template organization. The compiler does not search for definitions. (See C++ Programming Guide.)