On 02/21/2014 08:31 AM, Edward Diener wrote:
On 2/16/2014 3:56 PM, Vladimir Batov wrote:
Addressed all three comments... I think. Checked in.
This looks good.
Thanks, Edward, it's much appreciated.
I think you have successfully focused on what is needed for a more flexible lexical_cast-like version this time.
I am especially surprised by the fact that its performance seems quite adequate (without any optimization): user-defined type: lcast/convert=0.52/0.27 seconds. int type: scanf/lcast/convert=0.12/0.16/0.21 seconds. It beats lexical_cast for user-defined types and not that far behind for built-in types (I tested with "int"). I have a few doubts though regarding the performance tests as lexical_cast documentation lists quite different results: scanf: 24 string-to-int 7 std::stringstream without construction (my convert): 20 and puts lexical_cast so far in front for gcc 4.6.3 that I used for tests. On the other hand the test could not be any more straightforward: double p4 = clock(); for (int k = 0; k < local::num_cycles; ++k) sscanf("12345", "%d", &v); double p5 = clock(); for (int k = 0; k < local::num_cycles; ++k) boost::lexical_cast<int>("12345"); double p6 = clock(); for (int k = 0; k < local::num_cycles; ++k) boost::convert<int>::from("12345", ccnv).value(); double p7 = clock(); printf("scanf/lcast/convert=%.2f/%.2f/%.2f seconds.\n", (p5 - p4) / CLOCKS_PER_SEC, (p6 - p5) / CLOCKS_PER_SEC, (p7 - p6) / CLOCKS_PER_SEC); I have to say that when I read my own :-) documentation I do feel that "convert" provides quite useful functionality and quite a step forward compared to frugal lexical_cast (well, for my use anyway). What concerns me though is that when I look at the code, I think -- is it all?! There is so little of it that I can't help thinking -- I must be missing something monumental. V.