When SpacesInParentheses is set to true clang-format does not add a space before a global namespace variable. For example this is the output of clang-format for a somewhat contrived exampled.
#include <iostream> void print_val( std::ostream &s ) { s << "Hello world" << std::endl; } int main( void ) { print_val(::std::cout ); return 0; }
The .clang-format looked like
Language: Cpp SpacesInParentheses: true