Linker Tools Error LNK2022

metadata operation failed (HRESULT) : error_message

The linker detected an error while merging metadata. The metadata errors must be resolved to link successfully.

One way to diagnose this problem is to run ildasm -tokens on the object files to find which types have the tokens listed in error_message, and look for differences. In metadata, two different types with the same name is not valid, even if the just LayoutType attribute is different.

One reason for LNK2022 is when a type (such as a struct) exists in multiple compilands with the same name, but with conflicting definitions, and when you compile with /clr. In this case, make sure that the type has an identical definition in all compilands. The type name is listed in error_message.

Another possible cause for LNK2022 is when the linker finds a metadata file in a different ___location than was specified to the compiler (with #using ). Make sure that the metadata file (.dll or .netmodule) is in the same ___location when passed to the linker, as it was when it was passed to the compiler.

When building an ATL application, the use of the macro _ATL_MIXED is required in all compilands, if it is used in at least one.

Examples

The following sample defines an empty type.

// LNK2022_a.cpp
// compile with: /clr /c
public ref class Test {};

This sample shows that you cannot link two source code files that contain types of the same name but different definitions.

The following sample generates LNK2022.

// LNK2022_b.cpp
// compile with: LNK2022_a.cpp /clr /LD
// LNK2022 expected
public ref class Test {
   void func() {}
   int var;
};