Pedantic gcc 警告:函数返回类型的类型限定符

When I compiled my C++ code with GCC 4.3 for the first time, (after having compiled it successfully with no warnings on 4.1, 4.0, 3.4 with the -Wall -Wextra options) I suddenly got a bunch of errors of the form warning: type qualifiers ignored on function return type.

考虑 temp.cpp:

class Something
{
public:
    const int getConstThing() const {
        return _cMyInt;
    }
    const int getNonconstThing() const {
        return _myInt;
    }

    const int& getConstReference() const {
        return _myInt;
    }
    int& getNonconstReference() {
        return _myInt;
    }

    void setInt(const int newValue) {
        _myInt = newValue;
    }

    Something() : _cMyInt( 3 ) {
        _myInt = 2;
    }
private:
    const int _cMyInt;
    int _myInt;
};

运行g++ temp.cpp -Wextra -c -o blah.o:

temp.cpp:4: warning: type qualifiers ignored on function return type
temp.cpp:7: warning: type qualifiers ignored on function return type

谁能告诉我我做错了什么违反了 C++ 标准?我想当按值返回时，前导 const 是多余的，但我无法理解为什么需要用它生成警告.还有其他地方我应该去掉 const 吗?