Struct BooleanContext 

pub struct BooleanContext(Void);

Implementor of SubstParseContext for booleans

No values of this type are ever created - it’s just a generic parameter, used to select the associated marker types (and their constructor methods( in SubstParseContext.

So it can be uninhabited.

Tuple Fields

0: Void

Trait Implementations

impl Debug for BooleanContext

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

Formats the value using the given formatter.

impl SubstParseContext for BooleanContext

const IS_BOOL: bool = true

Whether this is a boolean context

type NotInPaste = ()

Uninhabited iff this lexical context is within ${paste }

type NotInConcat = ()

Uninhabited iff this lexical context is within ${concat }

type NotInBool = Void

Uninhabited iff this lexical context is within a condition.

type ConcatOnly = Void

Uninhabited unless this lexical context is within ${concat }

type BoolOnly = ()

Uninhabited unless this lexical context is within a condition.

type DbgContent = Subst<BooleanContext>

Content of the dbg keyword

type SpecialParseContext = ()

For communicating through parse_special

fn not_in_paste(_: &impl Spanned) -> Result<()>

fn not_in_concat(_: &impl Spanned) -> Result<()>

fn bool_only(_: &impl Spanned) -> Result<()>

fn meta_recog_usage(_: &SubstMeta<Self>) -> UsageInfo<IsUsed>

When we find a fmeta etc. in this context, does it allow a value?

fn not_in_bool(span: &impl Spanned) -> Result<Void>

fn missing_keyword_arguments(kw_span: Span) -> Result<Void>

Return an error suitable for reporting missing arguments

fn concat_only(span: &impl Spanned) -> Result<Self::ConcatOnly>

fn parse_maybe_within_parens<T>( input: ParseStream<'_>, f: impl FnOnce(ParseStream<'_>) -> Result<T>, ) -> Result<T>

Parse using f, within parens in boolean context, not otherwise

fn parse_maybe_comma(input: ParseStream<'_>) -> Result<()>

Parse maybe a comma (comma in boolean contegxt, not otherwise)