[glacier] Create lib with scaffolding string class.

lib/glacier/string/string.cpp

@@ -0,0 +1,37 @@
+#include "string/string.h"
+
+namespace glcr {
+namespace {
+
+uint64_t cstrlen(const char* cstr) {
+  uint64_t len = 0;
+  while (*cstr != '\0') {
+    cstr++;
+    len++;
+  }
+  return len;
+}
+
+}  // namespace
+
+String::String(const char* str) {
+  length_ = cstrlen(str);
+  cstr_ = new char[length_ + 1];
+  for (uint64_t i = 0; i <= length_; i++) {
+    cstr_[i] = str[i];
+  }
+}
+
+bool String::operator==(const String& other) {
+  if (other.length_ != length_) {
+    return false;
+  }
+  for (uint64_t i = 0; i < length_; i++) {
+    if (cstr_[i] != other.cstr_[i]) {
+      return false;
+    }
+  }
+  return true;
+}
+
+}  // namespace glcr