remove_const_t is an alias to the return type of the bsl::remove_const meta-function. Note, that the remove_const_t avoids the ::type suffix and typename prefix when we want to use the result of the meta-function in templates.
Declared in <bslmf_removeconst.h>
template<class t_TYPE>
using remove_const_t = remove_const<t_TYPE>::type;