I think you’re reading those stats incorrectly. They show that Python is up to about 400 times slower than C++ and with the exception of a single case, Python is more of a memory hog. When it comes to source size though, Python wins flat out. My experiences with Python show the same definite trend … Read more
Simply use std::chrono. The general example below times the task “of printing 1000 stars”: Instead of printing the stars, you will place your sorting algorithm there and time measure it. Do not forget to enable the optimization flags for your compiler, if you intend to do some benchmarking, e.g. for g++, you need -O3. This is serious, check … Read more
Dynamic linking can reduce total resource consumption (if more than one process shares the same library (including the version in “the same”, of course)). I believe this is the argument that drives it its presence in most environments. Here “resources” includes disk space, RAM, and cache space. Of course, if your dynamic linker is insufficiently flexible there is … Read more
A lot of people are saying that once you get to the size where speed is actually a concern that HashSet<T> will always beat List<T>, but that depends on what you are doing. Let’s say you have a List<T> that will only ever have on average 5 items in it. Over a large number of cycles, if a single item … Read more
There is no difference. Reason: Books on-line says “COUNT ( { [ [ ALL | DISTINCT ] expression ] | * } )“ “1” is a non-null expression: so it’s the same as COUNT(*). The optimizer recognizes it for what it is: trivial. The same as EXISTS (SELECT * … or EXISTS (SELECT 1 … Example: Same IO, same plan, … Read more
The first way is easier to maintain. Each declaration is a single statement on a single line, so you can easily add, remove, and reorder the declarations. With the second way, it is annoying to remove the first or last declaration because they start from the var keyword and finish with the semicolon respectively. Every time you … Read more
Gcc 7.1 -O3 these are all identical, godbolt.org/z/a-hc1d – jterm Apr 25 at 3:27 Original answer: Did some digging. Below is an example program and the relevant assembly: Code: Assembly: This was compiled with -std=c++11 -O2. You can see that there is quite a lot more work for the return “”; statement and comparably little for return std::string and return {}; (these … Read more
hash_set is an extension that is not part of the C++ standard. Lookups should be O(1) rather than O(log n) for set, so it will be faster in most circumstances. Another difference will be seen when you iterate through the containers. set will deliver the contents in sorted order, while hash_set will be essentially random (Thanks Lou Franco). Edit: The C++11 … Read more
The difference is that apply lets you invoke the function with arguments as an array; call requires the parameters be listed explicitly. A useful mnemonic is “A for array and C for comma.” See MDN’s documentation on apply and call. Pseudo syntax: theFunction.apply(valueForThis, arrayOfArgs) theFunction.call(valueForThis, arg1, arg2, …) There is also, as of ES6, the possibility to spread the array for use with the call function, you can see the compatibilities here. Sample code: