[concept_check][ublas] Fixing deprecated copy warnings

From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2022-02-07 06:31:35

Hi,

There are two PR that fix deprecated copy warnings for GCC and Clang:
* https://github.com/boostorg/concept_check/pull/35
* https://github.com/boostorg/ublas/pull/153

Please review those. They make the intent explicit and the code
becomes more portable.

Trivial sample that causes the warning https://godbolt.org/z/YaPvGfedv

-- 
Best regards,
Antony Polukhin