understanding modem.gammod and modulate

I want to convert a Matlab code to C++ code using codegen feature. That specific code uses two unsupported function in C++. One of the workaround was suggested by my professor is to obtain the output of those variables by running them in the command.

I ran the function h=modem.qammod(M) for M= 16

I got,

             Type: 'QAM Modulator'
                M: 16
      PhaseOffset: 0
    Constellation: [1x16 double]
      SymbolOrder: 'Binary'
    SymbolMapping: [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]
        InputType: 'Integer'

Then ran x_0 = modulate(h,[0:M-1]), and got a matrix.

Now I am trying to understand the output of modem.qammod, because I am trying to get ride of it.

So what is the output that it get shoved into modulate(h,..)

[Sajid Sarwar]

which MATLAB version are you using?