Feature | Adds std::string_view overloads for logger accessor

[BenLeadbetter]

Adds std::string_view overloads for logger accessor

Motivation

For clients who store logger ids as string literals, or other non-std::string data types, it would be very useful to add a std::string_view overload for the spdlog::get function. This would save such clients needing to make a temporary, dynamically allocated copy of their logger name data in order to access a specific logger.

Details

Only enabled in C++17

std::string_view is a C++17 feature, so the additional overloads are only included if the project is compiled against C++17 or greater.

Additional const char* overload

With the addition of the spdlog::get(std::string_view) overload, calls to this function with a const char* become ambiguous.

const char *const name = "my_logger";
spdlog::get(name); // error: call to spdlog::get is ambiguous.

To disambiguate we also add a spdlog::get(const char*) overload which forwards calls on to the spdlog::get(std::string_view) overload.

[BenLeadbetter]

@gabime Any idea what's happening with this gcc 7 check? Looks like a git error?

[gabime]

Merged. Thanks. The gcc 7 is a git workflow issue indeed

[gabime]

@BenLeadbetter I had to revert this since it caused backward compatabilty problems for c++17 that links to spdlog that compiled with c++11. See #3081

[BenLeadbetter]

Ah, that's a shame.

Fortunately the project for which the feature was intended went in a different direction in terms of it's spdlog integration.

In case you're interested, we had issues with the mutex locking in the registry on calls to splog::get, so we ended up writing a custom non-blocking registry for our loggers.