Enum Constant 

pub enum Constant {
    Adt(ConstValue),
    Str(String),
    Binary(Vec<u8>),
    Char(char),
    Int(u128),
    F16(u16),
    F32(f32),
    F64(f64),
    F128(u128),
    Bool(bool),
    Vec(Vec<Self>),
    Repeat(Box<Self>, u64),
    Tuple(Vec<Self>),
    RawPtr(u128),
    Ref(Box<Self>),
    Err,
}

A LitKind-like enum to fold constant Exprs into.

Variants

Adt(ConstValue)

A constant representing an algebraic data type

Str(String)

A String (e.g., “abc”).

Binary(Vec<u8>)

A binary string (e.g., b"abc").

Char(char)

A single char (e.g., 'a').

Int(u128)

An integer’s bit representation.

F16(u16)

An f16 bitcast to a u16.

F32(f32)

An f32.

F64(f64)

An f64.

F128(u128)

An f128 bitcast to a u128.

Bool(bool)

true or false.

Vec(Vec<Self>)

An array of constants.

Repeat(Box<Self>, u64)

Also an array, but with only one constant, repeated N times.

Tuple(Vec<Self>)

A tuple of constants.

RawPtr(u128)

A raw pointer.

Ref(Box<Self>)

A reference

Err

A literal with syntax error.

Implementations

impl Constant

pub fn partial_cmp( tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self, ) -> Option<Ordering>

Returns an ordering between left and right, if one exists. cmp_type determines comparison behavior for constants with ambiguous typing (ex. Constant::Int, which may be signed or unsigned).

Panics

Panics if the compared type is ambiguous and cmp_type describes a nonsensical type. For example, if left and right are Constant::Int, cmp_type.kind() must be either Int or Uint.

pub fn int_value(&self, tcx: TyCtxt<'_>, val_type: Ty<'_>) -> Option<FullInt>

Returns the integer value or None if self or val_type is not integer type.

pub fn peel_refs(self) -> Self

Consume Constant::Ref, removing all references to return the contained expression, e.g. &&T -> T.

fn parse_f16(s: &str) -> Self

fn parse_f128(s: &str) -> Self

pub fn new_numeric_min<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Self>

Create a constant representing the minimum value of the type described by ty, if one is defined.

pub fn new_numeric_max<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Self>

Create a constant representing the maximum value of the type described by ty, if one is defined.

pub fn is_numeric_min<'tcx>(&self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool

Checks whether self is a numeric of the type ty and whether self is the minimum value of that type.

pub fn is_numeric_max<'tcx>(&self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool

Checks whether self is a numeric of the type ty and whether self is the maximum value of that type.

pub fn is_pos_infinity(&self) -> bool

Checks whether self is a floating-point value representing positive infinity.

pub fn is_neg_infinity(&self) -> bool

Checks whether self is a floating-point value representing negative infinity.

Trait Implementations

impl Clone for Constant

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Constant

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for Constant

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Constant

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

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: 32 bytes

Size for each variant:

• Adt: 32 bytes
• Str: 32 bytes
• Binary: 32 bytes
• Char: 12 bytes
• Int: 32 bytes
• F16: 10 bytes
• F32: 12 bytes
• F64: 16 bytes
• F128: 32 bytes
• Bool: 9 bytes
• Vec: 32 bytes
• Repeat: 24 bytes
• Tuple: 24 bytes
• RawPtr: 32 bytes
• Ref: 16 bytes
• Err: 0 bytes