You can call the following functions.

• sample_var0();
• sample_var1();
• sample_var2();
• sample_var3();
• sample_loop1();
• sample_loop2();
• sample_loop3();
• sample_if_2();
• sample_for_1();
• sample_match_1();
• sample_match_2();
• sample_match_3();
• sample_enum_2();
• lesson1_scope_and_drop();
• lesson2_move_semantics();
• lesson3_ownership_and_func();
• lesson4_reference();
• lesson5_mutable_reference();