Add AsSpan() convenience method to fxcrt strings.

Make consistent with StringView methods.

Change-Id: Idf336895053a327262de924b6a525052e22a25da
Reviewed-on: https://pdfium-review.googlesource.com/30491
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

4 files changed, 24 insertions, 0 deletions

diff --git a/core/fxcrt/bytestring.h b/core/fxcrt/bytestring.h
index c68d2f6991..247238573d 100644
--- a/core/fxcrt/bytestring.h
+++ b/core/fxcrt/bytestring.h
@@ -84,6 +84,14 @@ class ByteString {
     return ByteStringView(raw_str(), GetLength());
   }
 
+  // Explicit conversion to span.
+  // Note: Any subsequent modification of |this| will invalidate the result.
+  pdfium::span<const char> AsSpan() const {
+    return m_pData ? pdfium::span<const char>(m_pData->m_String,
+                                              m_pData->m_nDataLength)
+                   : pdfium::span<const char>();
+  }
+
   // Note: Any subsequent modification of |this| will invalidate iterators.
   const_iterator begin() const { return m_pData ? m_pData->m_String : nullptr; }
   const_iterator end() const {
diff --git a/core/fxcrt/bytestring_unittest.cpp b/core/fxcrt/bytestring_unittest.cpp
index 8dab4f0cba..d030535edd 100644
--- a/core/fxcrt/bytestring_unittest.cpp
+++ b/core/fxcrt/bytestring_unittest.cpp
@@ -23,6 +23,10 @@ TEST(ByteString, ElementAccess) {
   EXPECT_DEATH({ abc[3]; }, ".*");
 #endif
 
+  pdfium::span<const char> abc_span = abc.AsSpan();
+  EXPECT_EQ(3u, abc_span.size());
+  EXPECT_EQ(0, memcmp(abc_span.data(), "abc", 3));
+
   ByteString mutable_abc = abc;
   EXPECT_EQ(abc.c_str(), mutable_abc.c_str());
   EXPECT_EQ('a', mutable_abc[0]);
diff --git a/core/fxcrt/widestring.h b/core/fxcrt/widestring.h
index f6c24375a0..b668b0292c 100644
--- a/core/fxcrt/widestring.h
+++ b/core/fxcrt/widestring.h
@@ -79,6 +79,14 @@ class WideString {
     return WideStringView(c_str(), GetLength());
   }
 
+  // Explicit conversion to span.
+  // Note: Any subsequent modification of |this| will invalidate the result.
+  pdfium::span<const wchar_t> AsSpan() const {
+    return m_pData ? pdfium::span<const wchar_t>(m_pData->m_String,
+                                                 m_pData->m_nDataLength)
+                   : pdfium::span<const wchar_t>();
+  }
+
   // Note: Any subsequent modification of |this| will invalidate iterators.
   const_iterator begin() const { return m_pData ? m_pData->m_String : nullptr; }
   const_iterator end() const {
diff --git a/core/fxcrt/widestring_unittest.cpp b/core/fxcrt/widestring_unittest.cpp
index ad91249c8e..ec0a55fc1e 100644
--- a/core/fxcrt/widestring_unittest.cpp
+++ b/core/fxcrt/widestring_unittest.cpp
@@ -21,6 +21,10 @@ TEST(WideString, ElementAccess) {
   EXPECT_DEATH({ abc[4]; }, ".*");
 #endif
 
+  pdfium::span<const wchar_t> abc_span = abc.AsSpan();
+  EXPECT_EQ(3u, abc_span.size());
+  EXPECT_EQ(0, wmemcmp(abc_span.data(), L"abc", 3));
+
   WideString mutable_abc = abc;
   EXPECT_EQ(abc.c_str(), mutable_abc.c_str());
   EXPECT_EQ(L'a', mutable_abc[0]);