How can I enumerate available voices and languages using espeak API?

I am using espeak API from C++ to do some simple text to speech synthesis from my embedded app. Currently, I have copied this line from the basic example on how to get started:

espeak_SetVoiceByName("default"); 

This seems to work fine, however I know that espeak comes with several voices in several different languages. How can I enumerate those and later select them using espeak API?

The documentation for espeak API is the headerfile itself. You can find it here.

To enumerate existing voices, you can use something like this:

const espeak_VOICE **list=espeak_ListVoices(0);
espeak_VOICE *voice=0;
for(;*list!=0;++list){
    voice=*list;
    if(0!=voice){
        //Look at voice parameters such has voice->name here
    }
}

Later when you have found a voice you want to use, you can set it with this:

if(0!=voice){
    espeak_SetVoiceByProperties(voice);
}

The espeak_VOICE struct is defined like this:

typedef struct {
    const char *name;      // a given name for this voice. UTF8 string.
    const char *languages;       // list of pairs of (byte) priority + (string) language (and dialect qualifier)
    const char *identifier;      // the filename for this voice within espeak-data/voices
    unsigned char gender;  // 0=none 1=male, 2=female,
    unsigned char age;     // 0=not specified, or age in years
    unsigned char variant; // only used when passed as a parameter to espeak_SetVoiceByProperties
    unsigned char xx1;     // for internal use
    int score;       // for internal use
    void *spare;     // for internal use
} espeak_VOICE;