大约有 31,500 项符合查询结果(耗时:0.0481秒) [XML]

https://stackoverflow.com/ques... 

std::string to char*

... It won't automatically convert (thank god). You'll have to use the method c_str() to get the C string version. std::string str = "string"; const char *cstr = str.c_str(); Note that it returns a const char *; you aren't allowed to change the...
https://stackoverflow.com/ques... 

How can I convert an RGB image into grayscale in Python?

... SciPy's image I/O is literally PIL/Pillow. Hence, testing SciPy is effectively retesting PIL/Pillow with negligible overhead introduced by SciPy's wrapper functions. It would have been much more useful to substitute OpenCV (which does not leverage PIL...
https://stackoverflow.com/ques... 

Why does integer overflow on x86 with GCC cause an infinite loop?

...efined behavior, it means it. Anything can happen. "Anything" includes "usually integers wrap around, but on occasion weird stuff happens". Yes, on x86 CPUs, integers usually wrap the way you expect. This is one of those exceptions. The compiler assumes you won't cause undefined behavior, and optim...
https://stackoverflow.com/ques... 

String concatenation in Ruby

...ficient in term of memory/speed from what I've seen (not measured though). All three methods will throw an uninitialized constant error when ROOT_DIR is nil. When dealing with pathnames, you may want to use File.join to avoid messing up with pathname separator. In the end, it is a matter of taste....
https://stackoverflow.com/ques... 

Join/Where with LINQ and Lambda

...re post.ID == id select new { Post = post, Meta = meta }; If you're really stuck on using lambdas though, your syntax is quite a bit off. Here's the same query, using the LINQ extension methods: var id = 1; var query = database.Posts // your starting point - table in the "from" statement ...
https://stackoverflow.com/ques... 

When to use Amazon Cloudfront or S3

...When end users request an object using this domain name, they are automatically routed to the nearest edge location for high performance delivery of your content. (Amazon) The data served by CloudFront may or may not come from S3. Since it is more optimized for delivery speed, the bandwidth costs ...
https://stackoverflow.com/ques... 

How to define an enumerated type (enum) in C?

...ollowing works without any complaints (compiled with gcc -ansi -pedantic -Wall): #include <stdio.h> enum { RANDOM, IMMEDIATE, SEARCH } strategy = IMMEDIATE; int main(int argc, char** argv){ printf("strategy: %d\n", strategy); return 0; } If instead of the above, the second line wer...
https://stackoverflow.com/ques... 

How do I delete unpushed git commits?

I accidentally committed to the wrong branch. How do I delete that commit? 7 Answers 7...
https://stackoverflow.com/ques... 

How to create Android Facebook Key Hash?

I do not understand this process at all. I have been able to navigate to the folder containing the keytool in the Java SDK. Although I keep getting the error openssl not recognised as an internal or external command. The problem is even if I can get this to work, what would I do and with what afterw...
https://stackoverflow.com/ques... 

Invert “if” statement to reduce nesting

...cked this code from the refactoring catalog. This specific refactoring is called: Replace Nested Conditional with Guard Clauses. share | improve this answer | follow ...