c++ - Using extern to refer to a function defined in a different compilation unit -

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due static data, have function

void foo(mynamespace::bar)

defined in compilation unit. point of use in compilation unit. use

namespace mynamespace {     extern void foo(bar); }

but linker can't find function definition. misusing extern?

extern can used kind of thing.

your problem linker expecting function mynamespace::foo(bar); due fact extern statement within mynamespace.

you have 2 choices:

  1. use extern void foo(mynamespace::bar); @ "point of use". don't enclose line within mynamespace.

  2. alternatively, enclose function definition within mynamespace.


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