Something

    GLuint *textures = (GLuint*)malloc(2*sizeof(GLuint));
    textures[0] = ta.tex;
    textures[1] = tb.tex;
    GLboolean *resid = (GLboolean*)malloc(2*sizeof(GLboolean));
    memset(resid, 0, 2*sizeof(GLboolean));
    glAreTexturesResident(2, textures, resid);
    
    printf("ta: %d\ntb: %d\n", (uint)resid[0], (uint)resid[1]);