CXX-3325 address -Wdeprecated-literal-operator warnings

[eramongodb]

Resolves CXX-3325.

The ""_bson user-defined literal (UDL) was introduced in #724. At the time, it was declared as (ignoring export macros):

document::value operator"" _bson(const char* str, size_t len);

#1066 attempted to reformat this declaration to address the -Wdeprecated-literal-operator warning observed with newer Clang compilers (per Compiler Explorer, supported since Clang 17 and enabled by default since Clang 20):

error: identifier '_bson' preceded by whitespace in a literal operator declaration is deprecated [-Werror,-Wdeprecated-literal-operator]

document::value operator""_bson(const char* json, size_t len);

but this had to be reverted by #1194 to restore compatibility with GCC 4.8 (which does not implement CWG 1473, prior to which a space between "" and ud-suffix was unfortunately mandatory; see this comment):

error: missing space between '""' and suffix identifier document::value operator""_bson(const char* json, size_t len);

However, following #1415, GCC 4.8 is no longer within our range of supported (minimum required) compilers. Therefore, we can now (re-)apply the proper fix (removing the space) without further issue.

Important

Following #1415, users on Red Hat 7 or older are expected to use a "Red Hat Developer Toolset" (DTS) or "GCC Toolset" to obtain a sufficiently recent GCC compiler version (GCC 8.1 or newer).

Note

There does not seem to be a ClangFormat option to control this behavior...?