ABACUS also provides several basic data structures as templates. For several fundamental types and some ABACUS classes the templates are instantiated already in the library libabacus.a. However, if you want to use one of the ABACUS templates for one of your classes then you have to instantiate the templates for these classes yourself.
Moreover, in order to keep the library small, we instantiated the templates only for those types which are required in the kernel of the ABACUS system. Therefore, it can happen that the linker complains about undefined symbols. In this case you have to instantiate these templates, too.
ABACUS allows implicit or explicit template instantiation. Implicit template instantiation is the more convenient way. The compiler automatically instantiates a template when required. Its disadvantage is that it increases the compile time and (depending on the compiler) also the size of the generated code. For explicit template instantiation the templates have to be collected manually in file and and this file has to be compiled separately. Note, some compilers do not support explicit template instantiation. Other compilers perform the explicit template instantiation automatically even if the implicit instantiation is selected. Currently, we recommend explicit template instantiation for the GNU-compiler 2.7.x and the SGI compiler and implicit template instantiation for the GNU-compiler 2.8.x, the SUN compiler and the MS Visual C++ compiler.
For instance, you want to use an ABA_ARRAY template for your class MYCONSTRAINT and the fundamental type unsigned int, for which we have no instantiations in the library libabacus.a. Then you can instantiate explicitly the corresponding templates in a file myarray.cc.
The file myarray.cc should be compiled and linked together with your files and the library libabacus.a. In the file in which you are using the array templates only the file array.h should be included.
For more information on templates we refer to the documentation of the templates for the GNU compiler1 . We prefer the method using the g++ compiler flag -fno-implicit-templates.