[maccard]

Not if they're compiled by separate invocations of the compiler. If a.cpp and b.cpp both have a vector<string> and are compiled independently, the first tool that actually gets to see them both is likely a linker (or archiver but that's a glorified zip tool)

[amelius]

Ok, but if these functions are inlined, would a linker then be able to fold these definitions?

(Or are you assuming that a debug flag is used so that all inlined functions are not really inlined by the compiler?)

[jeffbee]

OK but removing functions that are identical and that have the same name is not "identical code folding". ICF is removing functions that have identical bodies and different names.