Implement fallible C++ functions
diff --git a/gen/include.rs b/gen/include.rs
index a4b416a..da6678d 100644
--- a/gen/include.rs
+++ b/gen/include.rs
@@ -18,6 +18,7 @@
 pub struct Includes {
     custom: Vec<String>,
     pub cstdint: bool,
+    pub cstring: bool,
     pub memory: bool,
     pub string: bool,
     pub type_traits: bool,
@@ -41,6 +42,9 @@
         if self.cstdint {
             writeln!(f, "#include <cstdint>")?;
         }
+        if self.cstring {
+            writeln!(f, "#include <cstring>")?;
+        }
         if self.memory {
             writeln!(f, "#include <memory>")?;
         }