With arrays taken care of by the first rule, the second rule makes sure that all the standard containers as well as all the user-defined ones that follow the standard sequence interface will work with range-basedforout of the box. For example, in ODB (an ORM for C++), we have the co...
很多语言都有Range-based for loops这个功能,现在C++终于知道把这个重要功能加进语法中了。这个功能实在不知道该怎么翻译,语文没有学到家。 基本语法 for ( range_declaration : range_expression) loop_statement 1. 比如说: 1. vector<int> vec; 2. vec.push_back( 1 ); 3. vec.push_back( 2 ); 4. ...
Range-Based for loop应该是一种语法糖,实际上编译器应该是当成普通的for循环来处理的。 从cppreference(https://en.cppreference.com/w/cpp/language/range-for)上可以得到印证。 Range-Based for loop的一般形式(省略了不相关的部分)实际上等价于下面的for循环 for ( item-declaration : range-initializer ) s...
C++11-14 第7讲 Range-based for loop(范围循环) 非常简单的一个点 #include<iostream> #include<initializer_list> #include<vector> using namespace std; int main() { for (int i : {1, 2, 3, 4, 5, 6}) { cout << i << endl; } vector<double> vec; for (auto i : vec) cout <...
When used with a (non-const) object that has copy-on-write semantics, the range-basedforloop may trigger a deep copy by (implicitly) calling the non-constbegin()member function. If that is undesirable (for instance because the loop is not actually modifying the object), it can be avoided...
基于范围的for循环, Range-based for loop http://en.cppreference.com/w/cpp/language/range-for 语法: for (range_declaration:range_expression)loop_statement for (一个变量名 : 可迭代范围) { //循环语句 } 变量名的类型可以是:容器元素的类型,容器元素的引用类型,auto...
直觉上`c`的类型应该是`const char&`,但是怎么推理得到`c`的类型呢?细究起来确实花了一番功夫。 使用auto声明的变量必须要给初始值,而这里的语法没有给初始值。Range-Based for loop应该是一种语法糖,实际上编译器应该是当成普通的for循环来处理的。
attr(optional) for ( range_declaration : range_expression ) loop_statement 将其解释为 { auto && __range = range_expression; for (auto __begin = begin_expr, __end = end_expr; __begin != __end; ++__begin) { range_declaration = *__begin; loop_statement } } 初始化右值引用为临...
The range-basedforloop follows this general format: for(declaration:expression){//do some loop stuff} C++ Here’s an simple example which prints all the elements in astd::vector: std::vector<int>v1={-1,3,5,-8,0};std::cout<<std::endl<<"v1: "<<std::endl;for(constauto&t:v1)...
一些C++11语言新特性 - Range-Based for Loops,1.Range-BasedforLoopsfor(decl:coll){statement}eg:for(inti:{2,3,5,7,9,13,17,19}){std::coutvec;...for(auto&elem:vec...