A C++ function to format an std::time_point as an ISO 8601 string.<\/p>\n
The C++ std chrono stuff is very useful but a bit of a head-wreck!\u00a0 One of the things I had problems with was how to take an std::time_point value and format it as a string with the fractional seconds \/ microseconds included.\u00a0 This sort of time resolution is often required for accurately time stamping machine vision images, especially when acquiring at\u00a0 high rates from multiple cameras – accurate timestamps allow you to compare images from different cameras that were taken at the ‘same time’.<\/p>\n
Anyway if you’re happy to wait for C++20 then you will have access to a format() function; but if you’re more eager to format your time strings now, then here is a function which may fit the bill, it (the function) has to jump through some hoops, but gets there in the end.<\/p>\n
Note:<\/strong> This function uses the std::chrono::system_clock but it could be converted (or templated) for other std clocks..<\/p>\n A C++ function to format an std::time_point as an ISO 8601 string. The C++ std chrono stuff is very useful but a bit of a head-wreck!\u00a0 One of the things I had problems with was how to take an std::time_point value and format it as a string with the fractional seconds \/ microseconds included.\u00a0 This […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[301],"tags":[],"class_list":["post-2551","post","type-post","status-publish","format-standard","hentry","category-by-kevin-godden"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\r\n\/\/ Licensed under the Apache License, Version 2.0 (the \"License\");\r\n\/\/ you may not use this file except in compliance with the License.\r\n\/\/ You may obtain a copy of the License at\r\n\/\/\r\n\/\/ http:\/\/www.apache.org\/licenses\/LICENSE-2.0\r\n\/\/\r\n\/\/ Unless required by applicable law or agreed to in writing, software\r\n\/\/ distributed under the License is distributed on an \"AS IS\" BASIS,\r\n\/\/ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r\n\/\/ See the License for the specific language governing permissions and\r\n\/\/ limitations under the License.\r\n\r\n\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\r\n\/\/ Format an std::time_point as an ISO 8601 string with fractional seconds to 6\r\n\/\/ decimal places, e.g. 2014-08-30T08:18:51.867479\r\n\/\/ Warning will not work for any date\/times before the start of the UNIX epoch.\r\n\/\/\r\n\r\n#include