[cfe-dev] Template Qualifier Removal Question

[Csaba Raduly via cfe-dev]

Hi Andrew,


On Mon, Aug 13, 2018 at 8:36 AM, Andrew Gozillon via cfe-dev
<cfe-dev at lists.llvm.org> wrote:
> Hi,
>
> I have a question relating to template metafunctions like remove_const that
> split a type from its qualifiers.
>
> I was wondering where in Clang the decision to remove const (or another
> qualifier or pointer) from a type is made when using templates and then
> where it's performed (the new type generated)?

Are you talking about std::remove_const (
https://en.cppreference.com/w/cpp/types/remove_cv ) ?

I have bad news: std::remove_const doesn't remove const from a type.
It merely creates another type.

>From the "Possible implementation" :

template< class T > struct remove_const          { typedef T type; };
template< class T > struct remove_const<const T> { typedef T type; };

remove_const<T> creates a new type ( remove_const<T>::type ) which is
exactly the same as T,
except if T is const, remove_const<T>::type isn't.


Csaba
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