template parameter

[funceval]

Hi,

I was using llvm and came across code that looked somewhat similar to
this:

template <class U>
class LoopBase
{
};

class Loop : public LoopBase<Loop>
{
};

I didn't quite understand what this syntax means and where it might be
required. Please explain.

Thanks

 

[Alf P. Steinbach]

* funceval:

I was using llvm and came across code that looked somewhat similar to
this:

template <class U>
class LoopBase
{
};

class Loop : public LoopBase<Loop>
{
};

I didn't quite understand what this syntax means and where it might be
required. Please explain.

It's known as the Curiously Recurring Template Pattern, or CRTP for short.

Essentially it allows a kind of compile time polymorphism with LoopBase
accessing or wrapping functionality provided by the derived class.

AltaVista it.


Cheers & hth.,

- Alf