Merge pull request #87 from dtolnay/integer128

Support i128 and u128 to tokens

Cargo.toml

@@ -12,7 +12,7 @@ readme = "README.md"
 include = ["Cargo.toml", "src/**/*.rs", "tests/**/*.rs", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 
 [dependencies]
-proc-macro2 = { version = "0.4.13", default-features = false }
+proc-macro2 = { version = "0.4.21", default-features = false }
 
 [features]
 default = ["proc-macro"]

build.rs

@@ -0,0 +1,48 @@
+use std::env;
+use std::process::Command;
+use std::str::{self, FromStr};
+
+// The rustc-cfg strings below are *not* public API. Please let us know by
+// opening a GitHub issue if your build environment requires some way to enable
+// these cfgs other than by executing our build script.
+fn main() {
+    let minor = match rustc_minor_version() {
+        Some(minor) => minor,
+        None => return,
+    };
+
+    // 128-bit integers stabilized in Rust 1.26:
+    // https://blog.rust-lang.org/2018/05/10/Rust-1.26.html
+    if minor >= 26 {
+        println!("cargo:rustc-cfg=integer128");
+    }
+}
+
+fn rustc_minor_version() -> Option<u32> {
+    let rustc = match env::var_os("RUSTC") {
+        Some(rustc) => rustc,
+        None => return None,
+    };
+
+    let output = match Command::new(rustc).arg("--version").output() {
+        Ok(output) => output,
+        Err(_) => return None,
+    };
+
+    let version = match str::from_utf8(&output.stdout) {
+        Ok(version) => version,
+        Err(_) => return None,
+    };
+
+    let mut pieces = version.split('.');
+    if pieces.next() != Some("rustc 1") {
+        return None;
+    }
+
+    let next = match pieces.next() {
+        Some(next) => next,
+        None => return None,
+    };
+
+    u32::from_str(next).ok()
+}

src/to_tokens.rs

@@ -143,6 +143,12 @@ primitive! {
     f64 => f64_suffixed
 }
 
+#[cfg(integer128)]
+primitive! {
+    i128 => i128_suffixed
+    u128 => u128_suffixed
+}
+
 impl ToTokens for char {
     fn to_tokens(&self, tokens: &mut TokenStream) {
         tokens.append(Literal::character(*self));

tests/conditional/integer128.rs

@@ -0,0 +1,11 @@
+#[test]
+fn test_integer128() {
+    let ii128 = -1i128;
+    let uu128 = 1u128;
+
+    let tokens = quote! {
+        #ii128 #uu128
+    };
+    let expected = "-1i128 1u128";
+    assert_eq!(expected, tokens.to_string());
+}

tests/test.rs

@@ -9,6 +9,11 @@ extern crate quote;
 use proc_macro2::{Ident, Span, TokenStream};
 use quote::TokenStreamExt;
 
+mod conditional {
+    #[cfg(integer128)]
+    mod integer128;
+}
+
 struct X;
 
 impl quote::ToTokens for X {