build(rust): vendor googletest crate

third_party/crates/rustversion-1.0.23/src/release.rs

@@ -0,0 +1,34 @@
+use crate::error::{Error, Result};
+use crate::iter::Iter;
+use crate::token;
+use proc_macro::Group;
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Release {
+    pub minor: u16,
+    pub patch: Option<u16>,
+}
+
+pub fn parse(paren: Group, iter: Iter) -> Result<Release> {
+    try_parse(iter).map_err(|()| Error::group(paren, "expected rustc release number, like 1.31"))
+}
+
+fn try_parse(iter: Iter) -> Result<Release, ()> {
+    let major_minor = token::parse_literal(iter).map_err(drop)?;
+    let string = major_minor.to_string();
+
+    if !string.starts_with("1.") {
+        return Err(());
+    }
+
+    let minor: u16 = string[2..].parse().map_err(drop)?;
+
+    let patch = if token::parse_optional_punct(iter, '.').is_some() {
+        let int = token::parse_literal(iter).map_err(drop)?;
+        Some(int.to_string().parse().map_err(drop)?)
+    } else {
+        None
+    };
+
+    Ok(Release { minor, patch })
+}