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Add E0011 explanation
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@ -176,6 +176,38 @@ struct X { x: (), }
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the heap at runtime, and therefore cannot be done at compile time.
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"##,
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E0011: r##"
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Using a user-defined operator on const/static variable is restricted to what
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can be evaluated at compile-time. Using an user-defined operator could call a
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user-defined function, which is not allowed.
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Bad example:
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```
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use std::ops::Index;
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struct Foo { a: u8 }
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impl ::std::ops::Index<u8> for Foo {
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type Output = u8;
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fn index<'a>(&'a self, idx: u8) -> &'a u8 { &self.a }
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}
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const a: Foo = Foo { a: 0u8 };
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const b: u8 = a[0]; // Index trait is defined by the user, bad!
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```
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Only operators on builtin types are allowed.
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Example:
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```
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const a: &'static [i32] = &[1, 2, 3];
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const b: i32 = a[0]; // Good!
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```
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"##,
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E0013: r##"
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Static and const variables can refer to other const variables. But a const
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variable cannot refer to a static variable. For example, `Y` cannot refer to `X`
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@ -899,7 +931,6 @@ fn bar(&self) -> i32 { self.0 }
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register_diagnostics! {
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E0011,
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E0014,
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E0016,
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E0017,
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