在R2中map()被重命名为transform(),因此实际新增的三个函数为transform(),and_then()和or_else()。 这些函数主要是避免手动检查optional值是否有效,比如: 一个使用的小例子: 错误的情况: 目前GCC 12,Clang 14,MSVC v19.32已经支持该特性。 3 std::expected(P0323) 该特性用于解决错误处理的问
#include <cstdlib> #include <iostream> #include <string> std::string say_hello() { return std::string("Hello, CMake superbuild world!"); } int main() { std::cout << say_hello() << std::endl; return EXIT_SUCCESS; } 项目结构如下,包含一个根目录CMakeLists.txt和一个src/CMakeLists...
可以使用算法transform_reduce而不是for_each来指定额外的缩减操作。 在for_each算法调用中,调用 lambda 函数时会引用连续的容器元素。但有时,为了访问外部数据数组或实现非本地模板,还必须知道元素的索引。 这可以通过在 C ++ C ++ 17 中的推力库(包括NVIDIA HPC SDK )和std::ranges::views::iota中提供的coun...
查找是谁调用transform::operator*(...)导致导常,查下有两处:PoseGraph2D::InitializeGlobalSubmapPoses、PoseGraph2D::ComputeConstraintsForNode,它们都可能抛出异常。 <cartographer>/mapping/internal/2d/pose_graph_2d.cc --- std::vector<SubmapId> PoseGraph2D::InitializeGlobalSubmapPoses( const int trajector...
(void)vfprintf(stderr, fmt, ap); va_end(ap); } Both the va_arg() and va_end() macros work the same for the old-style and ISO C versions. Because va_arg() changes the value of ap, the call to vfprintf() cannot be: (...
magic_get - std::tuple like methods for user defined types without any macro or boilerplate code. [Boost] meta - Header-only, non-intrusive and macro-free runtime reflection system in C++. [MIT] Nameof - Header-only C++17 library provides nameof macros and functions to obtain the simple ...
views::reverse una::views::transform una::views::filter una::views::drop una::views::take//In C++20, you can just use std::ranges variants of these ranges,//but always use una::views::reverse from this library//because std::views::reverse is not good enought for Unicode.//You use...
(void)fputs("warning: ", stderr); fmt = va_arg(ap, char *); (void)vfprintf(stderr, fmt, ap); va_end(ap); } Both the va_arg() and va_end() macros work the same for the old-style and ISO C versions. Because va_arg() changes the value of ap, the call to vfprintf...
P2442R1 Windowing Range Adaptors: views::chunk, views::slide VS 2022 17.3 23 P2443R1 views::chunk_by VS 2022 17.3 23 P2445R1 forward_like() VS 2022 17.4 23 P2446R2 views::as_rvalue VS 2022 17.4 23 P2465R3 Standard Library Modules std And ...
P2442R1 Windowing Range Adaptors: views::chunk, views::slide VS 2022 17.3 23 P2443R1 views::chunk_by VS 2022 17.3 23 P2445R1 forward_like() VS 2022 17.4 23 P2446R2 views::as_rvalue VS 2022 17.4 23 P2465R3 Standard Library Modules std And ...