Changes absl::crc32c_t insertion operator (<<) to return value as 0-padded hex instead of dec

PiperOrigin-RevId: 552927211
Change-Id: I0375d60a9df4cdfc694fe8d3b3d790f80fc614a1

absl/crc/BUILD.bazel

@@ -93,6 +93,7 @@ cc_library(
         "//absl/base:endian",
         "//absl/base:prefetch",
         "//absl/strings",
+        "//absl/strings:str_format",
     ],
 )
 

absl/crc/CMakeLists.txt

@@ -77,6 +77,7 @@ absl_cc_library(
     absl::dynamic_annotations
     absl::endian
     absl::prefetch
+    absl::str_format
     absl::strings
 )
 

absl/crc/crc32c.h

@@ -29,6 +29,7 @@
 #include <ostream>
 
 #include "absl/crc/internal/crc32c_inline.h"
+#include "absl/strings/str_format.h"
 #include "absl/strings/string_view.h"
 
 namespace absl {
@@ -175,7 +176,7 @@ crc32c_t RemoveCrc32cSuffix(crc32c_t full_string_crc, crc32c_t suffix_crc,
 //
 // Streams the CRC32C value `crc` to the stream `os`.
 inline std::ostream& operator<<(std::ostream& os, crc32c_t crc) {
-  return os << static_cast<uint32_t>(crc);
+  return os << absl::StreamFormat("%08x", static_cast<uint32_t>(crc));
 }
 
 ABSL_NAMESPACE_END

absl/crc/crc32c_test.cc

@@ -18,6 +18,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <sstream>
 #include <string>
 
 #include "gtest/gtest.h"
@@ -191,4 +192,22 @@ TEST(CRC32C, RemoveSuffix) {
 
   EXPECT_EQ(absl::RemoveCrc32cSuffix(crc_ab, crc_b, world.size()), crc_a);
 }
+
+TEST(CRC32C, InsertionOperator) {
+  {
+    std::ostringstream buf;
+    buf << absl::crc32c_t{0xc99465aa};
+    EXPECT_EQ(buf.str(), "c99465aa");
+  }
+  {
+    std::ostringstream buf;
+    buf << absl::crc32c_t{0};
+    EXPECT_EQ(buf.str(), "00000000");
+  }
+  {
+    std::ostringstream buf;
+    buf << absl::crc32c_t{17};
+    EXPECT_EQ(buf.str(), "00000011");
+  }
+}
 }  // namespace