SetArgs is not working when using gmock to mock a C function

I have a c++ function to test, and this c++ function will call a legacy C function, so I need to mock the C function using gmock. The C function is:

int functionA(const char key[3],char value[5]) 

Now I can create a mock object and set the return value for it. But I also need to set the value for the second argument, because the value for the second argument is the actual output, and return value is a just a return code. My code is .t.cpp is:

const char pa[3] = {0};
    char pb[5] = {0};
    char set[5] = {1};

    EXPECT_CALL(MockObj, functionA(pa, pb)).WillOnce(DoAll(SetArgPointee<1>(set), Return(2)));


    EXPECT_EQ( phatics_decode(pa, pb), 2);

I got compiling errors:

array used as initializer
   explicit SetArgumentPointeeAction(const A& value) : value_(value) {}

error: invalid conversion from 'const char*' to 'char' [-fpermissive]
     *::std::tr1::get<N>(args) = value_;

So what's wrong? Also, is there is a way to assert i set the argument correctly? After i set argument, will it be stored in "pb"? Thanks