大约有 44,000 项符合查询结果（耗时：0.0665秒） [XML]
How should one use std::optional?
... paper: N3672, std::optional:
optional<int> str2int(string); // converts int to string if possible
int get_int_from_user()
{
string s;
for (;;) {
cin >> s;
optional<int> o = str2int(s); // 'o' may or may not contain an int
if (o) { ...
How to efficiently concatenate strings in go
...
If you have a string slice that you want to efficiently convert to a string then you can use this approach. Otherwise, take a look at the other answers.
There is a library function in the strings package called Join:
http://golang.org/pkg/strings/#Join
A look at the code of Join s...
Why use non-member begin and end functions in C++11?
...sn't a use for it. Pointers are pointers, arrays are arrays. Arrays can be converted to a pointer to their first element implicitly, but the is still just a regular old pointer, with no distinction with others. Of course you can't get the "end" of a pointer, case closed.
– GMan...
Go > operators
... nice answer, I binary shifting seemed troublesome at first but converting the value to decimal with powers to 2 helps well to get it
– minhajul
Aug 20 '18 at 6:46
...
High Quality Image Scaling Library [closed]
...1 this works brilliantly! One issue you need to correct in this code is to convert the quality variable to a long prior to passing it to the encoder param or you will get a invalid parameter runtime exception.
– James
Aug 4 '10 at 18:00
...
Using current time in UTC as default value in PostgreSQL
...low link and search the page for UTC. On input, a timestamp with time zone converts the incoming value to utc and stores that value WITH NO TIME ZONE OR OFFSET INFORMATION. On output, the stored utc value is converted to a local time using time zone of the client if available. This type is all abou...
Why is String.chars() a stream of ints in Java 8?
... it rarely used at all. However it would be good to have a built-in way to convert back IntStream to the String. It can be done with .reduce(StringBuilder::new, (sb, c) -> sb.append((char)c), StringBuilder::append).toString(), but it's really long.
– Tagir Valeev
...
Calculate distance between 2 GPS coordinates
...s and seconds are out of 60 so S31 30' is -31.50 degrees.
Don't forget to convert degrees to radians. Many languages have this function. Or its a simple calculation: radians = degrees * PI / 180.
function degreesToRadians(degrees) {
return degrees * Math.PI / 180;
}
function distanceInKmBetwe...
How to store date/time and timestamps in UTC time zone with JPA and Hibernate
...C timezone (so that Hibernate will store dates in UTC), and you'll need to convert to whatever timezone desired when you display stuff (at least we do it this way).
At startup, we do:
TimeZone.setDefault(TimeZone.getTimeZone("Etc/UTC"));
And set the desired timezone to the DateFormat:
fmt.setTi...
How do I use the CONCAT function in SQL Server 2008 R2?
...rver, SELECT 'varchar(' + 5 + ')' throws the error "Conversion failed when converting the nvarchar value 'varchar(' to data type int", so I guess your answer doesn't hold.
– Alexander
Apr 6 '16 at 9:13
...