c++,xcode,templates , Template members in class


Template members in class

Question:

Tag: c++,xcode,templates

I am trying to include template member in non-template class. Here's example:

.h

class ncScript {
public:
 template<typename T> void RegisterConstant( T value, const char *N );
};

.cpp

template<> 
void RegisterConstant<int>( int value, const char * N ) {
     // Do something.
}

template<>
void RegisterConstant<bool>( bool value, const char * N ) {
     // Do something.
}

// and so on

But when I am trying to use it like:

_luaCache["myluafile"].RegisterConstant( 13, "myvariable" );   

I am getting the following error in Xcode ( LLVM compiler ):

Explicit specialization of 'RegisterConstant<int>' after instantiation.

Answer:

The error tells you that the class is instantiated before the compiler sees the specializations.

For example if it sees this, the class is either already instantiated or will be here.

_luaCache["myluafile"].RegisterConstant( 13, "myvariable" );

if the specializations are implemented later you will get an error.

simplest solution is putting the specializations declarations in the header ie.

template<>  
void RegisterConstant<int>( int value, const char * N );

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