C++ can local class reference be passed to a function?
I would like to know if the following is allowed:
template < class C >
void fu开发者_如何学JAVAnction(C&);
void function() {
class {} local;
function(local);
}
thanks
It's not allowed right now. But it's supported in C++0x. The current Standard says at 14.3.1/2
A local type, a type with no linkage, an unnamed type or a type compounded from any of these types shall not be used as a template-argument for a template type-parameter.
That said, if the function is also local, there's no problem
void f() {
class L {} local;
struct C {
static void function(L &l) {
// ...
}
};
C::function(local);
}
It's allowed if you use polymorphism instead of templates. Or if you don't need to extend the interface seen by function
, simple inheritance will do.
void function( ABC & );
void function() {
class special : public ABC {
virtual void moof() {}
} local;
function(local);
}
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