Editing Template (C++) (section)

=== Explicit template specialization ===

Sometimes, the programmer may decide to implement a special version of a function (or class) for a given set of template type arguments which is called an explicit specialization. In this way certain template types can have a specialized implementation that is optimized for the type or a more meaningful implementation than the generic implementation.
* If a class template is specialized by a subset of its parameters it is called [[partial template specialization]] (function templates cannot be partially specialized).
* If all of the parameters are specialized it is a ''full specialization''.

Explicit specialization is used when the behavior of a function or class for particular choices of the template parameters must deviate from the generic behavior: that is, from the code generated by the main template, or templates. For example, the template definition below defines a specific implementation of <code>max()</code> for arguments of type <code>const char*</code>:
<syntaxhighlight lang="cpp">
#include <cstring>

template<> 
const char* max(const char* a, const char* b) {
    // Normally, the result of a direct comparison
    // between two C strings is undefined behaviour;
    // using std::strcmp makes defined.
    return std::strcmp(a, b) > 0 ? a : b;
}
</syntaxhighlight>