C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Templates and friend operator          C++Talk.NET Forum Index -> C++ language (comp.lang.c++) View previous topic :: View next topic   Author Message Patrick Labatut Guest Posted: Tue Sep 27, 2005 3:02 pm    Post subject: Templates and friend operator The following code should compile fine with g++ 3.3 and 3.4. However if I instead put the friend operator* declaration right below the operator* member, g++ 3.4 won't compile it anymore. Could someone give me some explanation on this weird behaviour ? /*************************************************************************/ template<class FloatT> class Vector3; template<class FloatT> Vector3<FloatT> operator*(FloatT f, const Vector3<FloatT>& v); template<class FloatT> class Vector3 { public: Vector3(FloatT x, FloatT y, FloatT z) { this->v[0] = x; this->v[1] = y; this->v[2] = z; } friend Vector3<FloatT> operator*<>(FloatT f, const Vector3<FloatT>& v); FloatT operator*(const Vector3<FloatT>& v) const { return (this->v[0] * v.v[0] + this->v[1] * v.v[1] + this->v[2] * v.v[2]); } private: FloatT v[3]; }; template<class FloatT> Vector3<FloatT> operator*(FloatT f, const Vector3<FloatT>& v) { return Vector3<FloatT>(f * v.v[0], f * v.v[1], f * v.v[2]); } int main(int argc, char *argv[]) { Vector3<float> v(0, 0, 0), w(0, 0, 0); w = 2.0f * v; return 0; } Back to top Micha Guest Posted: Tue Sep 27, 2005 8:44 pm    Post subject: Re: Templates and friend operator Hi Patrick, could you send your error messages too? I'm having a pretty much similar problem. Micha Back to top Patrick Labatut Guest Posted: Wed Sep 28, 2005 8:17 am    Post subject: Re: Templates and friend operator On 2005-09-27, Micha <michael.andrassy (AT) gmail (DOT) com> wrote: Quote: could you send your error messages too? yoohoo.cpp:24: error: declaration of `operator*' as non-function yoohoo.cpp:24: error: expected `;' before '<' token yoohoo.cpp: In function `Vector3 Vector3<FloatT>&) [with FloatT = float]': yoohoo.cpp:40: instantiated from here yoohoo.cpp:27: error: `float Vector3<float>::v[3]' is private yoohoo.cpp:33: error: within this context yoohoo.cpp:27: error: `float Vector3<float>::v[3]' is private yoohoo.cpp:33: error: within this context yoohoo.cpp:27: error: `float Vector3<float>::v[3]' is private yoohoo.cpp:33: error: within this context Some people I already asked told me they were getting similar error messages with other compilers than g++ (however I don't know which compilers they tried). Back to top Marc Guest Posted: Wed Sep 28, 2005 9:29 am    Post subject: Re: Templates and friend operator Patrick Labatut wrote: Quote: Some people I already asked told me they were getting similar error messages with other compilers than g++ (however I don't know which compilers they tried). Sun Studio: Warning: A friend function with template-id name must have a template declaration in the nearest namespace. Where: While specializing "Vector3<float>". Where: Specialized in non-template code. Comeau: error: function "Vector3<FloatT>::operator*" is not a template friend Vector3<FloatT> operator*<>(FloatT f, const Vector3<FloatT>& v); ^ Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ language (comp.lang.c++) All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.