Cast "const char *" to StringRef is now implicit and constexpr.

base/common/StringRef.h

@@ -27,17 +27,17 @@ struct StringRef
     size_t size = 0;
 
     template <typename CharT, typename = std::enable_if_t<sizeof(CharT) == 1>>
-    StringRef(const CharT * data_, size_t size_) : data(reinterpret_cast<const char *>(data_)), size(size_) {}
+    constexpr StringRef(const CharT * data_, size_t size_) : data(reinterpret_cast<const char *>(data_)), size(size_) {}
 
     StringRef(const std::string & s) : data(s.data()), size(s.size()) {}
-    StringRef(const std::string_view & s) : data(s.data()), size(s.size()) {}
-    explicit StringRef(const char * data_) : data(data_), size(strlen(data_)) {}
-    StringRef() = default;
+    constexpr StringRef(const std::string_view & s) : data(s.data()), size(s.size()) {}
+    constexpr StringRef(const char * data_) : StringRef(std::string_view{data_}) {}
+    constexpr StringRef() = default;
 
     std::string toString() const { return std::string(data, size); }
 
     explicit operator std::string() const { return toString(); }
-    explicit operator std::string_view() const { return {data, size}; }
+    constexpr explicit operator std::string_view() const { return {data, size}; }
 };
 
 using StringRefs = std::vector<StringRef>;

dbms/src/IO/WriteHelpers.h

@@ -239,11 +239,6 @@ inline void writeFloatText(T x, WriteBuffer & buf)
 }
 
 
-inline void writeString(const String & s, WriteBuffer & buf)
-{
-    buf.write(s.data(), s.size());
-}
-
 inline void writeString(const char * data, size_t size, WriteBuffer & buf)
 {
     buf.write(data, size);

dbms/src/Interpreters/Context.cpp

@@ -947,7 +947,7 @@ void Context::setSettings(const Settings & settings_)
 }
 
 
-void Context::setSetting(const String & name, const String & value)
+void Context::setSetting(const StringRef & name, const String & value)
 {
     auto lock = getLock();
     if (name == "profile")
@@ -962,7 +962,7 @@ void Context::setSetting(const String & name, const String & value)
 }
 
 
-void Context::setSetting(const String & name, const Field & value)
+void Context::setSetting(const StringRef & name, const Field & value)
 {
     auto lock = getLock();
     if (name == "profile")

dbms/src/Interpreters/Context.h

@@ -344,8 +344,8 @@ public:
     void setSettings(const Settings & settings_);
 
     /// Set settings by name.
-    void setSetting(const String & name, const String & value);
-    void setSetting(const String & name, const Field & value);
+    void setSetting(const StringRef & name, const String & value);
+    void setSetting(const StringRef & name, const Field & value);
     void applySettingChange(const SettingChange & change);
     void applySettingsChanges(const SettingsChanges & changes);