Safe FFI between Rust and C++
diff --git a/src/cxxbridge.cc b/src/cxxbridge.cc
new file mode 100644
index 0000000..3d1a902
--- /dev/null
+++ b/src/cxxbridge.cc
@@ -0,0 +1,168 @@
+#include "../include/cxxbridge.h"
+#include <cstring>
+#include <memory>
+#include <stdexcept>
+
+namespace cxxbridge = cxxbridge00;
+
+extern "C" {
+const char *cxxbridge00$cxx_string$data(const std::string &s) noexcept {
+  return s.data();
+}
+
+size_t cxxbridge00$cxx_string$length(const std::string &s) noexcept {
+  return s.length();
+}
+
+// RustString
+void cxxbridge00$rust_string$new(cxxbridge::RustString *self) noexcept;
+void cxxbridge00$rust_string$clone(cxxbridge::RustString *self,
+                                   const cxxbridge::RustString &other) noexcept;
+bool cxxbridge00$rust_string$from(cxxbridge::RustString *self, const char *ptr,
+                                  size_t len) noexcept;
+void cxxbridge00$rust_string$drop(cxxbridge::RustString *self) noexcept;
+const char *
+cxxbridge00$rust_string$ptr(const cxxbridge::RustString *self) noexcept;
+size_t cxxbridge00$rust_string$len(const cxxbridge::RustString *self) noexcept;
+
+// RustStr
+bool cxxbridge00$rust_str$valid(const char *ptr, size_t len) noexcept;
+} // extern "C"
+
+namespace cxxbridge00 {
+
+RustString::RustString() noexcept { cxxbridge00$rust_string$new(this); }
+
+RustString::RustString(const RustString &other) noexcept {
+  cxxbridge00$rust_string$clone(this, other);
+}
+
+RustString::RustString(RustString &&other) noexcept {
+  this->repr = other.repr;
+  cxxbridge00$rust_string$new(&other);
+}
+
+RustString::RustString(const char *s) {
+  auto len = strlen(s);
+  if (!cxxbridge00$rust_string$from(this, s, len)) {
+    throw std::invalid_argument("data for RustString is not utf-8");
+  }
+}
+
+RustString::RustString(const std::string &s) {
+  auto ptr = s.data();
+  auto len = s.length();
+  if (!cxxbridge00$rust_string$from(this, ptr, len)) {
+    throw std::invalid_argument("data for RustString is not utf-8");
+  }
+}
+
+RustString::~RustString() noexcept { cxxbridge00$rust_string$drop(this); }
+
+RustString::operator std::string() const {
+  return std::string(this->data(), this->size());
+}
+
+RustString &RustString::operator=(const RustString &other) noexcept {
+  if (this != &other) {
+    cxxbridge00$rust_string$drop(this);
+    cxxbridge00$rust_string$clone(this, other);
+  }
+  return *this;
+}
+
+RustString &RustString::operator=(RustString &&other) noexcept {
+  if (this != &other) {
+    cxxbridge00$rust_string$drop(this);
+    this->repr = other.repr;
+    cxxbridge00$rust_string$new(&other);
+  }
+  return *this;
+}
+
+const char *RustString::data() const noexcept {
+  return cxxbridge00$rust_string$ptr(this);
+}
+
+size_t RustString::size() const noexcept {
+  return cxxbridge00$rust_string$len(this);
+}
+
+size_t RustString::length() const noexcept {
+  return cxxbridge00$rust_string$len(this);
+}
+
+std::ostream &operator<<(std::ostream &os, const RustString &s) {
+  os.write(s.data(), s.size());
+  return os;
+}
+
+RustStr::RustStr() noexcept
+    : repr(Repr{reinterpret_cast<const char *>(this), 0}) {}
+
+RustStr::RustStr(const char *s) : repr(Repr{s, strlen(s)}) {
+  if (!cxxbridge00$rust_str$valid(this->repr.ptr, this->repr.len)) {
+    throw std::invalid_argument("data for RustStr is not utf-8");
+  }
+}
+
+RustStr::RustStr(const std::string &s) : repr(Repr{s.data(), s.length()}) {
+  if (!cxxbridge00$rust_str$valid(this->repr.ptr, this->repr.len)) {
+    throw std::invalid_argument("data for RustStr is not utf-8");
+  }
+}
+
+RustStr::RustStr(const RustStr &) noexcept = default;
+
+RustStr &RustStr::operator=(RustStr other) noexcept {
+  this->repr = other.repr;
+  return *this;
+}
+
+RustStr::operator std::string() const {
+  return std::string(this->data(), this->size());
+}
+
+const char *RustStr::data() const noexcept { return this->repr.ptr; }
+
+size_t RustStr::size() const noexcept { return this->repr.len; }
+
+size_t RustStr::length() const noexcept { return this->repr.len; }
+
+RustStr::RustStr(Repr repr_) noexcept : repr(repr_) {}
+
+RustStr::operator Repr() noexcept { return this->repr; }
+
+std::ostream &operator<<(std::ostream &os, const RustStr &s) {
+  os.write(s.data(), s.size());
+  return os;
+}
+
+} // namespace cxxbridge00
+
+extern "C" {
+void cxxbridge00$unique_ptr$std$string$null(
+    std::unique_ptr<std::string> *ptr) noexcept {
+  new (ptr) std::unique_ptr<std::string>();
+}
+void cxxbridge00$unique_ptr$std$string$new(std::unique_ptr<std::string> *ptr,
+                                           std::string *value) noexcept {
+  new (ptr) std::unique_ptr<std::string>(new std::string(std::move(*value)));
+}
+void cxxbridge00$unique_ptr$std$string$raw(std::unique_ptr<std::string> *ptr,
+                                           std::string *raw) noexcept {
+  new (ptr) std::unique_ptr<std::string>(raw);
+}
+const std::string *cxxbridge00$unique_ptr$std$string$get(
+    const std::unique_ptr<std::string> &ptr) noexcept {
+  return ptr.get();
+}
+std::string *cxxbridge00$unique_ptr$std$string$release(
+    std::unique_ptr<std::string> &ptr) noexcept {
+  return ptr.release();
+}
+void cxxbridge00$unique_ptr$std$string$drop(
+    std::unique_ptr<std::string> *ptr) noexcept {
+  ptr->~unique_ptr();
+}
+} // extern "C"