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Logical C++
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| // alignas C++11, C++14 | |
| class alignas(32) Foo {...} | |
| // address &foo is aligned to 32-byes boundary | |
| Foo foo{}; | |
| // it is not guarantee that address pFoo is aligned to 32-byes boundary | |
| Foo* pFoo = new Foo(); | |
| // there is no standard way to align heap-allocated addresses to a specific boundary in C++11 and C++14 | |
| // you can use C11 function aligned_alloc but C11 is not part of C++11/14 standards and therefore it is not portable | |
| ////////////////////////////////////////////////////////////////////// | |
| // if constexpr in C++17 | |
| // the code below does not compile, because if constexpt instantiates code not dependent on template parameters even in else branch | |
| #include <iostream> | |
| template <typename T> | |
| void test_print(T t) | |
| { | |
| if constexpr (std::is_integral_v<T>) | |
| { | |
| static_assert(sizeof(int)==1, "Hello from C++17"); | |
| } | |
| std::cout << t << std::endl; | |
| }; | |
| int main() | |
| { | |
| test_print(std::string("Hello World")); | |
| } | |
| // the code blow compiles necause static_assert depends on the template parameter T so the former one is eliminated | |
| #include <iostream> | |
| template <typename T> | |
| void test_print(T t) | |
| { | |
| if constexpr (std::is_integral_v<T>) | |
| { | |
| static_assert(sizeof(T)==1, "Hello from C++17"); | |
| } | |
| std::cout << t << std::endl; | |
| }; | |
| int main() | |
| { | |
| test_print(std::string("Hello World")); | |
| } | |
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