passing -Wshadow to gcc (v4.8.5) produces multiple warnings

[gabime]

e.g.

In file included from include/fmt/format.h:40:0,
                 from test.cpp:4:
include/fmt/core.h: In constructor ‘fmt::basic_string_view<Char>::basic_string_view(const Char*, size_t)’:
include/fmt/core.h:218:5: warning: declaration of ‘size’ shadows a member of 'this' [-Wshadow]
     : data_(s), size_(size) {}