c++ - C 中的 const 与 C++ 中的 const

Question

给定的代码在 C 中编译，但在 C++ 中失败。

int main()
{
   const int x; /* uninitialized const compiles in C but fails in C++*/
}

从 C 到 C++ 的转变背后的基本原理和原因是什么？

Answer 1

请参阅兼容性附录 C.1.6 中的规范:

7.1.6 [see also 3.5]

Change: const objects must be initialized in C++ but can be left uninitialized in C

Rationale: A const object cannot be assigned to so it must be initialized to hold a useful value.

Effect on original feature: Deletion of semantically well-defined feature.

Difficulty of converting: Semantic transformation.

How widely used: Seldom.