大约有 13,922 项符合查询结果（耗时：0.0240秒） [XML]
How much is too much with C++11 auto keyword?
... write the type at first sight, but the type of the right hand side of an expression is obvious. For example, using:
my_multi_type::nth_index<2>::type::key_type::composite_key_type::
key_extractor_tuple::tail_type::head_type::result_type
to get the composite key type in boost::multi_ind...
Standard concise way to copy a file in Java?
...om:
public static void copyFile(File sourceFile, File destFile) throws IOException {
if(!destFile.exists()) {
destFile.createNewFile();
}
FileChannel source = null;
FileChannel destination = null;
try {
source = new FileInputStream(sourceFile).getChannel();
...
If list index exists, do X
...
This doesn't account for negative indexes. The best way I know is try / except IndexError, but it'd be nice to have a concise way to get a bool
– Abram
Aug 6 '19 at 19:55
...
How does collections.defaultdict work?
I've read the examples in python docs, but still can't figure out what this method means. Can somebody help? Here are two examples from the python docs
...
How to detect if app is being built for device or simulator in Swift
...detect iOS on a desktop architecture like follows
#if (arch(i386) || arch(x86_64)) && os(iOS)
...
#endif
After Swift 4.1 version
Latest use, now directly for all in one condition for all types of simulators need to apply only one condition -
#if targetEnvironment(simulator)
...
An efficient way to transpose a file in Bash
...eel free to delete if you disapprove).
Maybe this version with some more explicit variable names will help answer some of the questions below and generally clarify what the script is doing. It also uses tabs as the separator which the OP had originally asked for so it'd handle empty fields and it c...
Mapping over values in a python dictionary
...s() method instead of .items() to save memory. The dict comprehension syntax wasn't introduced until python 2.7.
Note that there is no such method on lists either; you'd have to use a list comprehension or the map() function.
As such, you could use the map() function for processing your dict as we...
Android screen size HDPI, LDPI, MDPI [duplicate]
...your emulator. 240 is hdpi, 160 is mdpi and below that are usually ldpi.
Extract from Android Developer Guide link above:
320dp: a typical phone screen (240x320 ldpi, 320x480 mdpi, 480x800 hdpi, etc).
480dp: a tweener tablet like the Streak (480x800 mdpi).
600dp: a 7” tablet (600x1024 mdpi)....
How are parameters sent in an HTTP POST request?
... that the content type specifies.
Usually the content type is application/x-www-form-urlencoded, so the request body uses the same format as the query string:
parameter=value&also=another
When you use a file upload in the form, you use the multipart/form-data encoding instead, which has a di...