[libc-commits] [libc] [libc] Wchar Stringconverter (PR #146388)

[Uzair Nawaz via libc-commits]

================
@@ -0,0 +1,113 @@
+//===-- Definition of a class for mbstate_t and conversion -----*-- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_STRING_CONVERTER_H
+#define LLVM_LIBC_SRC___SUPPORT_STRING_CONVERTER_H
+
+#include "hdr/types/char32_t.h"
+#include "hdr/types/char8_t.h"
+#include "hdr/types/size_t.h"
+#include "src/__support/common.h"
+#include "src/__support/error_or.h"
+#include "src/__support/wchar/character_converter.h"
+#include "src/__support/wchar/mbstate.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace internal {
+
+template <typename T> class StringConverter {
+private:
+  CharacterConverter cr;
+  const T *src;
+  size_t src_len;
+  size_t src_idx;
+  size_t num_pushed;
+  size_t num_to_write;
+
+  int pushFullCharacter() {
+    for (num_pushed = 0; !cr.isFull() && src_idx + num_pushed < src_len;
+         ++num_pushed) {
+      int err = cr.push(src[src_idx + num_pushed]);
+      if (err != 0)
+        return err;
+    }
+
+    // if we aren't able to read a full character from the source string
+    if (src_idx + num_pushed == src_len && !cr.isFull()) {
+      src_idx += num_pushed;
+      return -1;
+    }
+
+    return 0;
+  }
+
+public:
+  StringConverter(const T *s, size_t srclen, size_t dstlen, mbstate *ps)
+      : cr(ps), src(s), src_len(srclen), src_idx(0), num_pushed(0),
+        num_to_write(dstlen) {
+    pushFullCharacter();
----------------
uzairnawaz wrote:

The other constructor actually just calls this one! Might be easy to miss with all the variable initializations going on but I don't think that's worth a comment unless you feel otherwise. 

https://github.com/llvm/llvm-project/pull/146388