Make: Rust 1.65 compatibility

Until then `f32::abs` is missing

Author: ashvardanian

CONTRIBUTING.md

@@ -209,6 +209,13 @@ cargo bench
 open target/criterion/report/index.html
 ```
 
+To automatically detect the Minimum Supported Rust Version (MSRV):
+
+```sh
+cargo +stable install cargo-msrv
+cargo msrv find --ignore-lockfile
+```
+
 ## JavaScript
 
 ### NodeJS

Cargo.toml

@@ -16,15 +16,16 @@ categories = [
   "wasm",
   "external-ffi-bindings",
 ]
-include = ["/rust/**", "/c/**", "/include/**", "/build.rs"]
+rust-version = "1.64" # Introduced Core C FFI in stable Rust
+include = ["rust/**", "c/**", "include/**", "build.rs"]
 
 
 [lib]
 name = "simsimd"
 path = "rust/lib.rs"
 
 [build-dependencies]
-cc = "1.0.83"
+cc = "1.2.36"
 
 
 [[bench]]
@@ -48,6 +49,6 @@ default = []
 std = []
 
 [dev-dependencies]
-criterion = { version = "0.6.0" }
+criterion = { version = "0.7.0" }
 rand = { version = "0.9.1" }
 half = { version = "2.6.0" }

build.rs

@@ -2,14 +2,14 @@ fn main() -> Result<(), cc::Error> {
     let mut build = cc::Build::new();
 
     build
+        // Prefer portable flags to support MSVC and older toolchains
+        .std("c99") // Enforce C99 standard when supported
         .file("c/lib.c")
         .include("include")
         .define("SIMSIMD_NATIVE_F16", "0")
         .define("SIMSIMD_NATIVE_BF16", "0")
         .define("SIMSIMD_DYNAMIC_DISPATCH", "1")
         .opt_level(3)
-        // Prefer portable flags to support MSVC and older toolchains
-        .flag_if_supported("-std=c99") // Enforce C99 standard when supported
         .flag_if_supported("-pedantic") // Strict compliance when supported
         .warnings(false);
 

rust/lib.rs

@@ -77,6 +77,12 @@
 pub type Distance = f64;
 pub type ComplexProduct = (f64, f64);
 
+/// Compatibility function for pre 1.85 Rust versions lacking `f32::abs`.
+#[inline(always)]
+fn f32_abs_compat(x: f32) -> f32 {
+    f32::from_bits(x.to_bits() & 0x7FFF_FFFF)
+}
+
 #[link(name = "simsimd")]
 extern "C" {
 
@@ -251,7 +257,7 @@ impl f16 {
     /// Returns the absolute value of self.
     #[inline(always)]
     pub fn abs(self) -> Self {
-        Self::from_f32(self.to_f32().abs())
+        Self::from_f32(f32_abs_compat(self.to_f32()))
     }
 
     /// Returns the largest integer less than or equal to a number.
@@ -425,7 +431,7 @@ impl bf16 {
     /// Returns the absolute value of self.
     #[inline(always)]
     pub fn abs(self) -> Self {
-        Self::from_f32(self.to_f32().abs())
+        Self::from_f32(f32_abs_compat(self.to_f32()))
     }
 
     /// Returns the largest integer less than or equal to a number.