I am writing matrix classes. Take a look at this definition: template <typename T, unsigned int dimension_x, unsigned int dimension_y> class generic_matrix { ... generic_matrix<T, dimension_x - 1, dimension_y - 1> minor(unsigned int x, unsigned int y) const { ... } ... } template <typename T, unsigned int dimension> class ...
Hi, I implemented a Simple STL map in C++. Factored out the comparison as a type as I was instructed to, then implemented the comparison as shown below: template <typename T> int KeyCompare<T>::operator () (T tKey1, T tKey2) { if(tKey1 < tKey2) return -1; else if(tKey1 > tKey2) return 1; else r...
I have following scenario: class my_base { ... } class my_derived : public my_base { ... }; template<typename X> struct my_traits. I want to specialize my_traits all classes derived from my_base including: i.e. template<typname Y> // Y is derived form my_base. stryct my_traits { ... }; I have no problems to add any tags, members...
I have a templated sparse_vector<T> class, and I am also using Boost UBLAS. How would I provide implicit conversions between sparse_vector<double> and boost::numeric::ublas::compressed_vector<double>? I would also like to provide similar conversions between std::vector<double> and boost::numeric::ublas::vector<double>. (I am using gcc...
For example: template<typename T> void write(T value) { mystream << value; } template<> void write<const char*>(const char* value) { write_escaped(mystream, value); } template<> void write<char*>(char* value) { write_escaped(mystream, value); } template<> void write<const std::string&>(const std::string& value) { writ...
Why is the following code invalid? template <typename S, typename T> struct B{ void f(T t, S s) {t.f<S>(s); } }; gcc 4.3.4 complains that it "expected primary-expression before '>' token", i.e. that "S" wasn't a valid primary-expression. ...
I have a class template <typename T> class C { static const int K=1; static ostream& print(ostream& os, const T& t) { return os << t;} }; I would like to specialize C for int. //specialization for int template <> C<int>{ static const int K=2; } I want the default print method that works for int to remain...
I'm writing a logging class that uses a templatized operator<< function. I'm specializing the template function on wide-character string so that I can do some wide-to-narrow translation before writing the log message. I can't get TCHAR to work properly - it doesn't use the specialization. Ideas? Here's the pertinent code: // Log.h head...
I have a template class that has a template member function that needs to be specialized, as in: template <typename T> class X { public: template <typename U> void Y() {} template <> void Y<int>() {} }; Altough VC handles this correctly, apperantly this isn't standard and GCC complains: explicit specialization in non-...
I would like to specialize a template method for a class C that is itself templated by an int parameter. How do I do this? template <int D=1> class C { static std::string foo () { stringstream ss; ss << D << endl; return ss.str();} }; template <class X> void test() { cout << "This is a test" << endl;} template <> template <...
Hi, Please, see what I am trying to do: #include <iostream> namespace first { template <class T> class myclass { T t; public: void who_are_you() const { std::cout << "first::myclass"; } }; } namespace second { using first::myclass; template <> class myclass <int> { int i, j; public: void who_are_you() const { std...
suppose I have a file alpha.h: class Alpha { public: template<typename T> void foo(); }; template<> void Alpha::foo<int>() {} template<> void Alpha::foo<float>() {} If I include alpha.h in more than one cpp file and compile with GCC 4.4, it complains there are multiple definitions of foo<int> and foo<float> across multiple object...
Consider this code: typedef int type1; typedef int type2; template <typename> struct some_trait; template <> struct some_trait<type1> { static const int something=1; }; template <> struct some_trait<type2> { static const int something=2; }; It fails because what the compiler sees is two specializations of some_trait<int>. ...
I have something like this in my code: template <typename T> struct A { void Print(); }; template <> struct A<char*> { void Print() { printf("Char*!\n"); } }; template <typename T> void DoSomething(T& lol) { A<T> a; a.Print(); } int main() { char a[5]; DoSomething(a); } And this produces the following linker error: err...
I'm trying to use SFINAE to distinguish a class that has a member called 'name'. I set things up in what seems to be the standard pattern but it's not working -- instead of silently ignoring the 'failed' substitution, the compiler produces an error. I'm sure I've run up against some template substitution rule, I'd be grateful if someon...
How to specialize a template defined in some external namespace in the body of my class? Concrete example using BGL which doesn't compile: class A { namespace boost { template <class ValueType> struct container_gen<SomeSelectorS, ValueType> { typedef std::multiset<ValueType,MyClass<ValueType> > type; }; } } ...
Consider something like... template<typename T> class Vector { ... bool operator==( const Vector<float> &rhs ) { // compare and return } bool operator==( const Vector<T> &rhs ) { // compare and return } ... }; Notice how the specialization is above the non specialized version. If I were to put the specialized ver...
I have a custom logging class that supports iostream-syntax via a templated operator <<: template< class T > MyLoggingClass & operator <<(MyLoggingClass &, const T &) { // do stuff } I also have a specialized version of this operator that is supposed to be called when a log-message is complete: template< > MyLoggingClass & operat...
The following code compiles properly. #include <string> template <typename T, typename U> class Container { private: T value1; U value2; public: Container(){} void doSomething(T val1, U val2); }; template<typename T, typename U> void Container<typename T, typename U>::doSomething(T val1, U val2) { ; // Some impleme...
My question is w.r.t the following thread : http://stackoverflow.com/questions/2009924/specialize-a-member-template-without-specializing-its-parent I'm absolutely fine with the standard saying that it is illegal to do so. But i want to understand why is it illegal to do so? What would be impact had it been allowed? ...