template<typename T> return_type fun_name();
template<> return_type fun_name<int>(){/* blabla */}

//-------------failed case-------------
template <typename T>
struct deduce{
    typedef T* type;
};


template  <typename T>
typename deduce<T>::type fun1();

template  <>
typename deduce<float>::type fun1<float>() //error if no "<float>" after fun1
{

}

//------------now the "Template Argument Deduction" works------------
template <typename T>
struct some_struct{
    T* p;
};

template  <typename T>
some_struct<T> fun2();

template  <>
some_struct<float> fun2() // no error even if no "<float>" after fun2
{

}

error: template-id ‘fun1<>’ for ‘float* fun1()’ does not match any template declaration