Question

I’m trying to understand why the following code doesn’t compile.

class X
{
public:
    template< typename T >
    void set( T & val )
    {
    }
};

int main( int c, char *v[] )
{
    X x;

    x.set( new int( 99 ) );        // 15
}

On my solaris compiler I get the following error.

"x.cpp", line 15: Error: Could not find a match for X::set<X::T>(int*) needed in main(int, char**).

I can’t work out why the compiler woudln’t take the reference of a pointer to an int and pass the type “T” as “int *”

Answer 1

It can, but that’s a temp 😉

class X
{
public:
    template< typename T >
    void set( T const & val )  // add const here
    {
    }
};

and you can’t bind it to a non-const reference.

Same reason why this would work:

class X
{
public:
    template< typename T >
    void set( T & val )
    {
    }
};
int main( int c, char *v[] )
{
    X x;
    int * y = new int( 99 );
    x.set( y );        // 15
}

here, y is no longer a temporary.