Trying to fix stdlib issue in tokenizers.

Author: Narsil

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "esaxx-rs"
-version = "0.1.9"
+version = "0.1.10"
 authors = ["Nicolas Patry <patry.nicolas@protonmail.com>"]
 edition = "2018"
 description = "Wrapping around sentencepiece's esaxxx library."

Cargo.toml

@@ -1,4 +1,5 @@
 #[cfg(feature = "cpp")]
+#[cfg(not(target_os = "macos"))]
 fn main() {
     cc::Build::new()
         .cpp(true)
@@ -9,5 +10,18 @@ fn main() {
         .compile("esaxx");
 }
 
+#[cfg(feature = "cpp")]
+#[cfg(target_os = "macos")]
+fn main() {
+    cc::Build::new()
+        .cpp(true)
+        .flag("-std=c++11")
+        .flag("-stdlib=libc++")
+        .static_crt(true)
+        .file("src/esaxx.cpp")
+        .include("src")
+        .compile("esaxx");
+}
+
 #[cfg(not(feature = "cpp"))]
 fn main() {}