大约有 30,000 项符合查询结果（耗时：0.0429秒） [XML]
What exactly does @synthesize do?
...et using the dot notation: myObject.mapView. A property doesn't have to be based on an ivar, but most properties are. The @propertydeclaration simply tells the world that there is a property called mapView.
@synthesize mapView = mapView1;
This line tells the compiler to create a setter and getter ...
Why does GCC generate 15-20% faster code if I optimize for size instead of speed?
... gcc-4.8.1 0.296s 0.288s
Update: on Ivy Bridge-based Core i3 three versions of gcc (4.6.4, 4.7.3, and 4.8.1) produce binaries with significantly different performance, but the assembly code has only subtle variations. So far, I have no explanation of this fact.
Assembly ...
Notepad++ Setting for Disabling Auto-open Previous Files
...our C:\Users\myuseraccount\AppData\Roaming\Notepad++ directory (Windows 7 x64). Mine was empty, meaning who know where the config was really coming from, but I copied over the file with the one in C:\Program Files (x86)\Notepad++ and now everything works just like you would expect it to.
...
C++ templates that accept only certain types
...
I suggest using Boost's static assert feature in concert with is_base_of from the Boost Type Traits library:
template<typename T>
class ObservableList {
BOOST_STATIC_ASSERT((is_base_of<List, T>::value)); //Yes, the double parentheses are needed, otherwise the comma will be...
Counting inversions in an array
... +1, See similar solution in C++11, including a general iterator-based solution and sample random testbed using sequences from 5-25 elements. Enjoy!.
– WhozCraig
Apr 20 '14 at 20:15
...
“x not in y” or “not x in y”
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
Draft saved
Draft discarded
...
“Too many values to unpack” Exception
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
Draft saved
Draft discarded
...
Get ffmpeg information in friendly way
...name": "Windows Media Video 9",
"codec_type": "video",
"codec_time_base": "1/1000",
"codec_tag_string": "WMV3",
"codec_tag": "0x33564d57",
"width": 320,
"height": 240,
"has_b_frames": 0,
"pix_fmt": "yuv420p",
"level": -99,
"r_frame_rate": "30000/1001",
"av...
How to check if a variable is a dictionary in Python?
... for help, clarification, or responding to other answers.Making statements based on opinion; back them up with references or personal experience.To learn more, see our tips on writing great answers.
Draft saved
Draft discarded
...
Convert a row of a data frame to vector
...
Here is a dplyr based option:
newV = df %>% slice(1) %>% unlist(use.names = FALSE)
# or slightly different:
newV = df %>% slice(1) %>% unlist() %>% unname()
...