mirror of
https://github.com/Light-City/CPlusPlusThings.git
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dfe1c933b3
- const README: rewrite the space-saving claim per issue #5 follow-ups (constant-expression const vs #define immediates; which const qualify as constant expressions) - const README: fix the class-section diagnosis per issue #338 (overload resolution picks the const overload; the restriction only surfaces once that overload is removed) - sizeof README: virtual-inheritance result is compiler-dependent (GCC merges vbptr+vfptr -> 16, MSVC keeps them separate -> 32) #246 - static README: new section on internal linkage / access restriction with anonymous-namespace comparison #142 - 10-day practice: full problem list table + fixed day links #136 - new design_pattern/singleton/singleton_default.hpp: reusable thread-safe CRTP singleton template, compile+concurrency tested #303
33 lines
1.3 KiB
Markdown
33 lines
1.3 KiB
Markdown
> 来自 [C++那些事网站](https://light-city.github.io/stories_things/stl-source-analysis/cpp-string-interview/) 的文章，由站点同步脚本导出。
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# STL string 面试题精讲
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今天给大家分享一个字符串相关的面试题目，总共有4个case，可以在留言区评论，说出这四处会发生什么。
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std::string大家应该非常熟悉了，std::string_view是17之后引入的视图，不懂的可以查阅一下，下面有两个字面量，分别是string子面量与string_view字面量，用`s`、`sv`代表。
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前两个问题都是函数返回一个std::string_view，但有些区别，一个是基于c-style string，另一个基于string。
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后面两个问题是从string字面量与string_view字面量构建。
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好了，问题描述清楚了，可以在留言区见了～
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```cpp
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std::string_view getBar() {
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std::string b{"it is bar."};
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return b;
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}
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std::string_view getFoo() {
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return "It is foo.";
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}
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using namespace std::string_literals;
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using namespace std::string_view_literals;
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std::cout << getFoo() << std::endl; // 1
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std::cout << getBar() << std::endl; // 2
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std::string_view svf{"Hello foo"s};
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std::cout << svf << std::endl; // 3
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std::string_view svff{"Hello foo"sv};
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std::cout << svff << std::endl; // 4
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``` |