在C++中缓存昂贵的数据 - 函数范围的静态与可变成员变量

int expensiveFunction() {
    static int cachedValue = 0;
    if (cachedValue == 0) {
        // 昂贵的计算操作
        cachedValue = someExpensiveOperation();
    }
    return cachedValue;
}

class MyClass {
public:
    int getExpensiveData() {
        if (!m_isDataCached) {
            // 昂贵的计算操作
            m_cachedData = someExpensiveOperation();
            m_isDataCached = true;
        }
        return m_cachedData;
    }

private:
    int m_cachedData = 0;
    bool m_isDataCached = false;
};