#[macro_export]
macro_rules! const_if {
($cond: expr => $if_true:expr;$if_false: expr) => {
[$if_false, $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;$if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr; else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr;elif $cond5: expr => $if_t5: expr; else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4;elif $cond5 => $if_t5; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr;elif $cond5: expr => $if_t5: expr;elif $cond6: expr => $if_t6:expr; else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4;elif $cond5 => $if_t5;elif $cond6 => $if_t6; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr;elif $cond5: expr => $if_t5: expr;elif $cond6: expr => $if_t6:expr;elif $cond7: expr => $if_t7:expr; else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4;elif $cond5 => $if_t5;elif $cond6 => $if_t6;elif $cond7 => $if_t7; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr;elif $cond5: expr => $if_t5: expr;elif $cond6: expr => $if_t6:expr;elif $cond7: expr => $if_t7:expr;elif $cond8: expr => $if_t8: expr;else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4;elif $cond5 => $if_t5;elif $cond6 => $if_t6;elif $cond7 => $if_t7;elif $cond8 => $if_t8; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr;elif $cond5: expr => $if_t5: expr;elif $cond6: expr => $if_t6:expr;elif $cond7: expr => $if_t7:expr;elif $cond8: expr => $if_t8: expr;elif $cond9: expr => $if_t9: expr;else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4;elif $cond5 => $if_t5;elif $cond6 => $if_t6;elif $cond7 => $if_t7;elif $cond8 => $if_t8;elif $cond9 => $if_t9; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr;elif $cond5: expr => $if_t5: expr;elif $cond6: expr => $if_t6:expr;elif $cond7: expr => $if_t7:expr;elif $cond8: expr => $if_t8: expr;elif $cond9: expr => $if_t9: expr;elif $cond10: expr => $if_t10: expr;else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4;elif $cond5 => $if_t5;elif $cond6 => $if_t6;elif $cond7 => $if_t7;elif $cond8 => $if_t8;elif $cond9 => $if_t9;elif $cond10 => $if_t10; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr; elif $cond3: expr => $if_t3: expr; elif $cond4: expr => $if_t4: expr;elif $cond5: expr => $if_t5: expr;elif $cond6: expr => $if_t6:expr;elif $cond7: expr => $if_t7:expr;elif $cond8: expr => $if_t8: expr;elif $cond9: expr => $if_t9: expr;elif $cond10: expr => $if_t10: expr;elif $cond11: expr => $if_t11: expr;else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;elif $cond3 => $if_t3;elif $cond4 => $if_t4;elif $cond5 => $if_t5;elif $cond6 => $if_t6;elif $cond7 => $if_t7;elif $cond8 => $if_t8;elif $cond9 => $if_t9;elif $cond10 => $if_t10;elif $cond11 => $if_t11; else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
elif $cond16: expr => $if_t16: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
elif $cond16 => $if_t16;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
elif $cond16: expr => $if_t16: expr;
elif $cond17: expr => $if_t17: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
elif $cond16 => $if_t16;
elif $cond17 => $if_t17;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
elif $cond16: expr => $if_t16: expr;
elif $cond17: expr => $if_t17: expr;
elif $cond18: expr => $if_t18: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
elif $cond16 => $if_t16;
elif $cond17 => $if_t17;
elif $cond18 => $if_t18;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
elif $cond16: expr => $if_t16: expr;
elif $cond17: expr => $if_t17: expr;
elif $cond18: expr => $if_t18: expr;
elif $cond19: expr => $if_t19: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
elif $cond16 => $if_t16;
elif $cond17 => $if_t17;
elif $cond18 => $if_t18;
elif $cond19 => $if_t19;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
elif $cond16: expr => $if_t16: expr;
elif $cond17: expr => $if_t17: expr;
elif $cond18: expr => $if_t18: expr;
elif $cond19: expr => $if_t19: expr;
elif $cond20: expr => $if_t20: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
elif $cond16 => $if_t16;
elif $cond17 => $if_t17;
elif $cond18 => $if_t18;
elif $cond19 => $if_t19;
elif $cond20 => $if_t20;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
elif $cond16: expr => $if_t16: expr;
elif $cond17: expr => $if_t17: expr;
elif $cond18: expr => $if_t18: expr;
elif $cond19: expr => $if_t19: expr;
elif $cond20: expr => $if_t20: expr;
elif $cond21: expr => $if_t21: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
elif $cond16 => $if_t16;
elif $cond17 => $if_t17;
elif $cond18 => $if_t18;
elif $cond19 => $if_t19;
elif $cond20 => $if_t20;
elif $cond21 => $if_t21;
else $if_false) , $if_true][$cond as usize]
};
($cond : expr => $if_true: expr; elif $cond2: expr => $if_t2:expr;
elif $cond3: expr => $if_t3: expr;
elif $cond4: expr => $if_t4: expr;
elif $cond5: expr => $if_t5: expr;
elif $cond6: expr => $if_t6:expr;
elif $cond7: expr => $if_t7:expr;
elif $cond8: expr => $if_t8: expr;
elif $cond9: expr => $if_t9: expr;
elif $cond10: expr => $if_t10: expr;
elif $cond11: expr => $if_t11: expr;
elif $cond12: expr => $if_t12: expr;
elif $cond13: expr => $if_t13: expr;
elif $cond14: expr => $if_t14: expr;
elif $cond15: expr => $if_t15: expr;
elif $cond16: expr => $if_t16: expr;
elif $cond17: expr => $if_t17: expr;
elif $cond18: expr => $if_t18: expr;
elif $cond19: expr => $if_t19: expr;
elif $cond20: expr => $if_t20: expr;
elif $cond21: expr => $if_t21: expr;
elif $cond22: expr => $if_t22: expr;
else $if_false:expr ) => {
[const_if!($cond2 => $if_t2;
elif $cond3 => $if_t3;
elif $cond4 => $if_t4;
elif $cond5 => $if_t5;
elif $cond6 => $if_t6;
elif $cond7 => $if_t7;
elif $cond8 => $if_t8;
elif $cond9 => $if_t9;
elif $cond10 => $if_t10;
elif $cond11 => $if_t11;
elif $cond12 => $if_t12;
elif $cond13 => $if_t13;
elif $cond14 => $if_t14;
elif $cond15 => $if_t15;
elif $cond16 => $if_t16;
elif $cond17 => $if_t17;
elif $cond18 => $if_t18;
elif $cond19 => $if_t19;
elif $cond20 => $if_t20;
elif $cond21 => $if_t21;
elif $cond22 => $if_t22;
else $if_false) , $if_true][$cond as usize]
};
}
mod tests {
const fn min(x: i32, y: i32) -> i32 {
const_if!(x < y => x;y)
}
#[test]
fn test_min() {
assert_eq!(min(2, 3), 2);
}
const fn int_to_str(i: i32) -> &'static str {
const_if!(
i == 0 => "Zero";
elif i == 1 => "One";
elif i == 2 => "Two";
elif i == 3 => "Three";
elif i == 4 => "Four";
elif i == 5 => "Five";
elif i == 6 => "Six";
elif i == 7 => "Seven";
elif i == 8 => "Eight";
elif i == 9 => "Nine";
elif i == 10 => "Ten";
else "Unknown"
)
}
#[test]
fn test_elif() {
assert_eq!(int_to_str(5), "Five");
}
#[test]
fn test_expanded() {
let i = 6;
assert_eq!(
[
[
[
[
[
[
[
[
[
[["Unknown", "Ten"][(i == 10) as usize], "Nine"]
[(i == 9) as usize],
"Eight",
][(i == 8) as usize],
"Seven",
][(i == 7) as usize],
"Six",
][(i == 6) as usize],
"Five",
][(i == 5) as usize],
"Four",
][(i == 4) as usize],
"Three",
][(i == 3) as usize],
"Two",
][(i == 2) as usize],
"One",
][(i == 1) as usize],
"Zero",
][(i == 0) as usize],
"Six"
);
}
}