rt.rs

#![allow(missing_debug_implementations)]
#![unstable(feature = "fmt_internals", issue = "none")]

//! These are the lang items used by format_args!().

#[lang = "format_placeholder"]
#[derive(Copy, Clone)]
pub struct Placeholder {
    pub position: usize,
    pub fill: char,
    pub align: Alignment,
    pub flags: u32,
    pub precision: Count,
    pub width: Count,
}

impl Placeholder {
    #[inline(always)]
    pub const fn new(
        position: usize,
        fill: char,
        align: Alignment,
        flags: u32,
        precision: Count,
        width: Count,
    ) -> Self {
        Self { position, fill, align, flags, precision, width }
    }
}

/// Possible alignments that can be requested as part of a formatting directive.
#[lang = "format_alignment"]
#[derive(Copy, Clone, PartialEq, Eq)]
pub enum Alignment {
    /// Indication that contents should be left-aligned.
    Left,
    /// Indication that contents should be right-aligned.
    Right,
    /// Indication that contents should be center-aligned.
    Center,
    /// No alignment was requested.
    Unknown,
}

/// Used by [width](https://doc.rust-lang.org/std/fmt/#width) and [precision](https://doc.rust-lang.org/std/fmt/#precision) specifiers.
#[lang = "format_count"]
#[derive(Copy, Clone)]
pub enum Count {
    /// Specified with a literal number, stores the value
    Is(usize),
    /// Specified using `$` and `*` syntaxes, stores the index into `args`
    Param(usize),
    /// Not specified
    Implied,
}