asio::config fails to query integer-based properties (wrong usage of max_digits10)

[manipuladordedados]

max_digits10 is only meaningful for floating-point types, and, at least on Linux/GCC/libstdc++, expands to 0 on any non-floating-point types. This causes buffers such as

asio/asio/include/asio/impl/config.hpp

Line 35 in 62481a2

char buf[std::numeric_limits<unsigned long long>::max_digits10 + 1];

to be 0-sized and fail to query the actual value for the desired property.

Code such as the following will always return 0:

asio::config cfg{ioctx}; 
return cfg.get("scheduler", "concurrency_hint", 1);