Will a "variableName;" C++ statement be a no-op at all times?

In C++ sometimes a variable will be defined, but not used. Here's an example - a function for use with COM_INTERFACE_ENTRY_FUNC_BLIND ATL macro:

HRESULT WINAPI blindQuery( void* /*currentObject*/, REFIID iid, void** ppv, DWORD_PTR /*param*/ ) 
{
    DEBUG_LOG( __FUNCTION__ ); //DEBUG_LOG macro expands to an empty string in non-debug
    DEBUG_LOG( iid );
    iid; // <<<<<<<----silence compiler warning
    if( ppv == 0 ) {
        return E_POINTER;
    }
    *ppv = 0;
    return E_NOINTERFACE;
}

In the above example iid parameter is used with DEBUG_LOG macro that expands into an empty string in non-debug configurations. So commenting out or removing the iid variable name in the signature is not an option. When non-debug configurations are being compiled the compiler spawns a C4100: 'iid' : unreferenced formal parameter warning, so in order to silence the warning the iid; statement that is believed to be a no-op is added.

The question is the following: if we have any of the following declarations:

 CSomeType variableName; //or
 CSomeType& variableName; //or
 CSomeType* variableName;

will the following statement in C++ code:

variableName;

be a no-op at all times independent of what CSomeType is?