enum BlockFrame {
    Statement {
        ignores_expr_result: bool,
    },
    TailExpr {
        tail_result_is_ignored: bool,
        span: Span,
    },
    SubExpr,
}

Variants

Statement

Fields

ignores_expr_result: bool

If true, then statement discards result from evaluating the expression (such as examples 1 and 2 above).

Evaluation is currently within a statement.

Examples include:

  1. EXPR;
  2. let _ = EXPR;
  3. let x = EXPR;

TailExpr

Fields

tail_result_is_ignored: bool

If true, then the surrounding context of the block ignores the result of evaluating the block’s tail expression.

Example: let _ = { STMT_1; EXPR };

span: Span

Span of the tail expression.

Evaluation is currently within the tail expression of a block.

Example: { STMT_1; STMT_2; EXPR }

SubExpr

Generic mark meaning that the block occurred as a subexpression where the result might be used.

Examples: foo(EXPR), match EXPR { ... }

Implementations

Trait Implementations

Formats the value using the given formatter. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 12 bytes

Size for each variant:

  • Statement: 1 byte
  • TailExpr: 11 bytes
  • SubExpr: 0 bytes