Add TrimString function

Author: psx95

api/include/opentelemetry/trace/propagation/detail/string.h

@@ -57,6 +57,30 @@ inline size_t SplitString(nostd::string_view s,
   return filled;
 }
 
+inline nostd::string_view TrimString(nostd::string_view s)
+{
+  size_t str_size = s.size();
+  size_t trimmed_str_start_pos = 0;
+  size_t trimmed_str_end_pos = 0;
+  bool start_pos_found = false;
+  for (size_t i = 0; i < str_size; i++)
+  {
+    if (!isspace(s[i]))
+    {
+      if (!start_pos_found)
+      {
+        trimmed_str_start_pos = i;
+        trimmed_str_end_pos = i;
+        start_pos_found = true;
+      } else
+      {
+        trimmed_str_end_pos = i;
+      }
+    }
+  }
+  return s.substr(trimmed_str_start_pos, trimmed_str_end_pos - trimmed_str_start_pos + 1);
+}
+
 }  // namespace detail
 }  // namespace propagation
 }  // namespace trace

api/test/trace/propagation/detail/BUILD

@@ -18,3 +18,19 @@ cc_test(
         "@com_google_googletest//:gtest_main",
     ],
 )
+
+cc_test(
+    name = "string_test",
+    srcs = [
+        "string_test.cc",
+    ],
+    tags = [
+        "api",
+        "test",
+        "trace",
+    ],
+    deps = [
+        "//api",
+        "@com_google_googletest//:gtest_main",
+    ],
+)

api/test/trace/propagation/detail/CMakeLists.txt

@@ -1,7 +1,7 @@
 # Copyright The OpenTelemetry Authors
 # SPDX-License-Identifier: Apache-2.0
 
-foreach(testname hex_test)
+foreach(testname hex_test string_test)
   add_executable(${testname} "${testname}.cc")
   target_link_libraries(${testname} ${GTEST_BOTH_LIBRARIES}
                         ${CMAKE_THREAD_LIBS_INIT} opentelemetry_api)

api/test/trace/propagation/detail/string_test.cc

@@ -0,0 +1,13 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include <gtest/gtest.h>
+#include <stdint.h>
+#include <string>
+
+#include "opentelemetry/nostd/string_view.h"
+
+TEST(StringTest, TrimStrings)
+{
+  //TODO(psx95): Add tests
+}