src/test/ui/consts/min_const_fn/min_const_fn.rs

   1 // ok
   2 const fn foo1() {}
   3 const fn foo2(x: i32) -> i32 { x }
   4 const fn foo3<T>(x: T) -> T { x }
   5 const fn foo7() {
   6     (
   7         foo1(),
   8         foo2(420),
   9         foo3(69),
  10     ).0
  11 }
  12 const fn foo12<T: Sized>(t: T) -> T { t }
  13 const fn foo13<T: ?Sized>(t: &T) -> &T { t }
  14 const fn foo14<'a, T: 'a>(t: &'a T) -> &'a T { t }
  15 const fn foo15<T>(t: T) -> T where T: Sized { t }
  16 const fn foo15_2<T>(t: &T) -> &T where T: ?Sized { t }
  17 const fn foo16(f: f32) -> f32 { f }
  18 const fn foo17(f: f32) -> u32 { f as u32 }
  19 const fn foo18(i: i32) -> i32 { i * 3 }
  20 const fn foo20(b: bool) -> bool { !b }
  21 const fn foo21<T, U>(t: T, u: U) -> (T, U) { (t, u) }
  22 const fn foo22(s: &[u8], i: usize) -> u8 { s[i] }
  23 const FOO: u32 = 42;
  24 const fn foo23() -> u32 { FOO }
  25 const fn foo24() -> &'static u32 { &FOO }
  26 const fn foo27(x: &u32) -> u32 { *x }
  27 const fn foo28(x: u32) -> u32 { *&x }
  28 const fn foo29(x: u32) -> i32 { x as i32 }
  29 const fn foo31(a: bool, b: bool) -> bool { a & b }
  30 const fn foo32(a: bool, b: bool) -> bool { a | b }
  31 const fn foo33(a: bool, b: bool) -> bool { a & b }
  32 const fn foo34(a: bool, b: bool) -> bool { a | b }
  33 const fn foo35(a: bool, b: bool) -> bool { a ^ b }
  34 struct Foo<T: ?Sized>(T);
  35 impl<T> Foo<T> {
  36     const fn new(t: T) -> Self { Foo(t) }
  37     const fn into_inner(self) -> T { self.0 } //~ destructors cannot be evaluated
  38     const fn get(&self) -> &T { &self.0 }
  39     const fn get_mut(&mut self) -> &mut T { &mut self.0 }
  40     //~^ mutable references in const fn are unstable
  41 }
  42 impl<'a, T> Foo<T> {
  43     const fn new_lt(t: T) -> Self { Foo(t) }
  44     const fn into_inner_lt(self) -> T { self.0 } //~ destructors cannot be evaluated
  45     const fn get_lt(&'a self) -> &T { &self.0 }
  46     const fn get_mut_lt(&'a mut self) -> &mut T { &mut self.0 }
  47     //~^ mutable references in const fn are unstable
  48 }
  49 impl<T: Sized> Foo<T> {
  50     const fn new_s(t: T) -> Self { Foo(t) }
  51     const fn into_inner_s(self) -> T { self.0 } //~ ERROR destructors
  52     const fn get_s(&self) -> &T { &self.0 }
  53     const fn get_mut_s(&mut self) -> &mut T { &mut self.0 }
  54     //~^ mutable references in const fn are unstable
  55 }
  56 impl<T: ?Sized> Foo<T> {
  57     const fn get_sq(&self) -> &T { &self.0 }
  58     const fn get_mut_sq(&mut self) -> &mut T { &mut self.0 }
  59     //~^ mutable references in const fn are unstable
  60 }
  61
  62
  63 const fn char_ops(c: char, d: char) -> bool { c == d }
  64 const fn char_ops2(c: char, d: char) -> bool { c < d }
  65 const fn char_ops3(c: char, d: char) -> bool { c != d }
  66 const fn i32_ops(c: i32, d: i32) -> bool { c == d }
  67 const fn i32_ops2(c: i32, d: i32) -> bool { c < d }
  68 const fn i32_ops3(c: i32, d: i32) -> bool { c != d }
  69 const fn i32_ops4(c: i32, d: i32) -> i32 { c + d }
  70 const fn char_cast(u: u8) -> char { u as char }
  71 const unsafe fn ret_i32_no_unsafe() -> i32 { 42 }
  72 const unsafe fn ret_null_ptr_no_unsafe<T>() -> *const T { core::ptr::null() }
  73 const unsafe fn ret_null_mut_ptr_no_unsafe<T>() -> *mut T { core::ptr::null_mut() }
  74
  75 // not ok
  76 const fn foo11<T: std::fmt::Display>(t: T) -> T { t }
  77 //~^ ERROR trait bounds other than `Sized` on const fn parameters are unstable
  78 const fn foo11_2<T: Send>(t: T) -> T { t }
  79 //~^ ERROR trait bounds other than `Sized` on const fn parameters are unstable
  80 const fn foo19(f: f32) -> f32 { f * 2.0 }
  81 //~^ ERROR only int, `bool` and `char` operations are stable in const fn
  82 const fn foo19_2(f: f32) -> f32 { 2.0 - f }
  83 //~^ ERROR only int, `bool` and `char` operations are stable in const fn
  84 const fn foo19_3(f: f32) -> f32 { -f }
  85 //~^ ERROR only int and `bool` operations are stable in const fn
  86 const fn foo19_4(f: f32, g: f32) -> f32 { f / g }
  87 //~^ ERROR only int, `bool` and `char` operations are stable in const fn
  88
  89 static BAR: u32 = 42;
  90 const fn foo25() -> u32 { BAR } //~ ERROR cannot access `static` items in const fn
  91 const fn foo26() -> &'static u32 { &BAR } //~ ERROR cannot access `static` items
  92 const fn foo30(x: *const u32) -> usize { x as usize }
  93 //~^ ERROR casting pointers to ints is unstable
  94 const fn foo30_with_unsafe(x: *const u32) -> usize { unsafe { x as usize } }
  95 //~^ ERROR casting pointers to ints is unstable
  96 const fn foo30_2(x: *mut u32) -> usize { x as usize }
  97 //~^ ERROR casting pointers to ints is unstable
  98 const fn foo30_2_with_unsafe(x: *mut u32) -> usize { unsafe { x as usize } }
  99 //~^ ERROR casting pointers to ints is unstable
 100 const fn foo30_6() -> bool { let x = true; x }
 101 const fn foo36(a: bool, b: bool) -> bool { a && b }
 102 //~^ ERROR loops and conditional expressions are not stable in const fn
 103 const fn foo37(a: bool, b: bool) -> bool { a || b }
 104 //~^ ERROR loops and conditional expressions are not stable in const fn
 105 const fn inc(x: &mut i32) { *x += 1 }
 106 //~^ ERROR mutable references in const fn are unstable
 107
 108 fn main() {}
 109
 110 impl<T: std::fmt::Debug> Foo<T> {
 111 //~^ ERROR trait bounds other than `Sized` on const fn parameters are unstable
 112     const fn foo(&self) {}
 113 }
 114
 115 impl<T: std::fmt::Debug + Sized> Foo<T> {
 116 //~^ ERROR trait bounds other than `Sized` on const fn parameters are unstable
 117     const fn foo2(&self) {}
 118 }
 119
 120 impl<T: Sync + Sized> Foo<T> {
 121 //~^ ERROR trait bounds other than `Sized` on const fn parameters are unstable
 122     const fn foo3(&self) {}
 123 }
 124
 125 struct AlanTuring<T>(T);
 126 const fn no_rpit2() -> AlanTuring<impl std::fmt::Debug> { AlanTuring(0) }
 127 //~^ ERROR `impl Trait` in const fn is unstable
 128 const fn no_apit2(_x: AlanTuring<impl std::fmt::Debug>) {}
 129 //~^ ERROR trait bounds other than `Sized`
 130 const fn no_apit(_x: impl std::fmt::Debug) {} //~ ERROR trait bounds other than `Sized`
 131 const fn no_rpit() -> impl std::fmt::Debug {} //~ ERROR `impl Trait` in const fn is unstable
 132 const fn no_dyn_trait(_x: &dyn std::fmt::Debug) {} //~ ERROR trait bounds other than `Sized`
 133 const fn no_dyn_trait_ret() -> &'static dyn std::fmt::Debug { &() }
 134 //~^ ERROR trait bounds other than `Sized`
 135
 136 const fn no_unsafe() { unsafe {} }
 137
 138 const fn really_no_traits_i_mean_it() { (&() as &dyn std::fmt::Debug, ()).1 }
 139 //~^ ERROR trait bounds other than `Sized`
 140
 141 const fn no_fn_ptrs(_x: fn()) {}
 142 //~^ ERROR function pointers in const fn are unstable
 143 const fn no_fn_ptrs2() -> fn() { fn foo() {} foo }
 144 //~^ ERROR function pointers in const fn are unstable