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c++templatessfinae

Define function outside template class that uses SFINAE?


In bellow sample I want to define destructor in this case outside the class, none of the trillion syntaxes I tried so far works:

    template<typename OjectType,
        typename = std::enable_if_t<std::is_base_of_v<SomeClass, OjectType>>>
    class SampleClass
    {
    public:
        ~SampleClass();
    };

    // How to define this outside class?
    template<typename ObjectType>
    SampleClass<ObjectType>::~SampleClass()
    {
    }

Solution

  • You were close, you forgot to specify the second template parameter (without the default value):

    template <typename ObjectType, typename Dummy>
    SampleClass<ObjectType, Dummy>::~SampleClass()
    {
        // ...
    }