–compat

Sets the major release compatibility mode of the compiler. 

–features=alst

Enables or disables various C++ language features. 

-xchar

Eases the migration of code from systems where the char type is defined as unsigned. 

–xldscope

Controls the default linker scope of variable and function definitions to create faster and safer shared libraries. 

–xthreadvar

(SPARC) Changes the default thread-local storage access mode. 

-xtrigraphs

Enables recognition of trigraph sequences. 

–xustr

Enables recognition of string literals composed of sixteen-bit characters.