Using macro to split a given argument

Question

Lets say we have a macro like this:

#define SOME_MACRO(a) ...do stuff

Now, calling the macro in this way:

SOME_MACRO(argName=1)

It should return only the first part of the given argument before = (just 'argName' in this case). Is it possible? Thank you in advance

Thank you all, this is my full problem: I'm using this macro to create an enum and a function to get the enum values as strings:

#define RA_MAKE_ENUMERATOR_S1(r, data, elem) case elem : return BOOST_PP_STRINGIZE(elem);
#define RA_MAKE_ENUMERATOR(name, enumerators)                                   \
enum name                                                                   \
{                                                                           \
    BOOST_PP_SEQ_ENUM(enumerators)                                          \
};                                                                          \
                                                                            \
inline const std::string ValueToString(name v)                              \
{                                                                           \
    switch (v)                                                              \
    {                                                                       \
        BOOST_PP_SEQ_FOR_EACH(RA_MAKE_ENUMERATOR_S1, name, enumerators) \
    }                                                                       \
}   

RA_MAKE_ENUMERATOR(eTest, (ONE) (TWO))

This outputs the following code:

enum eTest
{
    ONE, 
    TWO
}; 
inline const std::string ValueToString(eTest v)
{
    switch (v)
    {
         case ONE  : return "ONE"; 
         case TWO  : return "TWO";
    }
}

Which is perfect. But what is I want to assign a specific value to ONE and TWO like:

enum eTest
{
    ONE = 2, 
    TWO = 4
}; 

I tried calling the macro as

RA_MAKE_ENUMERATOR(eTest, (ONE=2) (TWO=2))

The enumerator is ok but of course the ValueToString function is messed up