BloombergLP::bdld::operator<<

Write the specified rhs value to the specified output stream in the format shown below: ` [ nnn = aa, mmm = bb]‐ nnn and mmm are key ints, while aa and bb are the result of invoking operator << on the individual value elements in the map ` and return a reference to the modifiable stream. The function will have no effect if the stream is not valid.