extern and unresolved external : I'm lost

[Sxilderik]

Hello all

I'm facing a very puzzling issue :

an array of const std::string values is never seen by the linker :

source1.cpp

#include <string>

extern const std::string foo[5];

void main(int n, char *v[])
{
	for (int i=0;i<_countof(foo);i++)
	{
		printf("\"%s\"\n",foo[i].c_str());
	}
}

source2.cpp

#include <string>

const std::string foo[5]={"bar","1","2"};

expected result:
"bar"
"1"
"2"
""
""

but that does not compile : liker chokes on

1>Linking...
1>source1.obj : error LNK2001: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const * const foo" (?foo@@3QBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@B)
1>D:\Dev\underCvs\addins\syncagx\trunk\Debug\test.exe : fatal error LNK1120: 1 unresolved externals

(Of course, both files are compiled and linked)

Can anyone help ?
Thanks !

[guestgulkan]

Try using the extern keyword in both source1.cpp and source2.cpp and see what happens.

[jsmith]

You are not linking both source1.obj and source2.obj into the executable.