How to check for the type of a template parameter?

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Use is_same:

#include <type_traits>

template <typename T>
void foo()
{
    if (std::is_same<T, animal>::value) { /* ... */ }  // optimizable...
}

Usually, that’s a totally unworkable design, though, and you really want to specialize:

template <typename T> void foo() { /* generic implementation  */ }

template <> void foo<animal>()   { /* specific for T = animal */ }

Note also that it’s unusual to have function templates with explicit (non-deduced) arguments. It’s not unheard of, but often there are better approaches.

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