从我在线阅读的内容来看,fmt 库应该比例如 stringstreams 快得多。
然而,我做了一些简单的基准测试(测量系统时间,见下面的代码),似乎 fmt 总是比 stringstreams 慢。我有什么问题吗?
uint64_t start;
uint64_t stop;
long MAXCOUNT = 10000000;
std::srand(123);
int* numbers = new int[MAXCOUNT];
for ( int i = 0; i < MAXCOUNT; i++) {
numbers[i] = std::rand();
}
{
std::string result;
start = currentTimeInMillis();
for ( int i = 0; i < MAXCOUNT; i++) {
result += fmt::format("Number {} is great!", numbers[i]);
}
stop = currentTimeInMillis();
fmt::print("timing fmt : {} ms / string length: {}\n", stop-start, result.size());
}
{
std::string …Run Code Online (Sandbox Code Playgroud)