2.1.85. --[no_]nonstd_qualifier_deduction
This option controls whether or not nonstandard template argument
deduction is to be performed in the qualifier portion of a qualified
name in C++.
With this feature enabled, a template argument for the template
parameter T can be deduced in contexts like A<T>::B or T::B.
The standard deduction mechanism treats these as non deduced contexts
that use the values of template parameters that were either explicitly
specified or deduced elsewhere.
Note
The option --nonstd_qualifier_deduction is
provided only as a migration aid for legacy source code that does
not conform to the C++ standard. Its use is not recommended.
This option is effective only if the source language is C++.
The default is --no_nonstd_qualifier_deduction.
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