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When to use symbols instead of strings in Ruby?
..., mode: "ascii")
# removed for brevity
end
write(data: 123, file: "test.txt")
freeze to keep as a string and save memory
label = 'My Label'.freeze
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64-bit version of Boost for 64-bit windows
...
I've got the built binaries on my site:
http://boost.teeks99.com
Edit 2013-05-13: My builds are now available (starting from 1.53) directly from the sourceforge page.
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[精华] VC中BSTR、Char和CString类型的转换 - C/C++ - 清泛网 - 专注C/C++及内核技术
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//判断字符串是否是某种类型
CString sValue("123.1");
COleVariant vValue(sValue);
BOOL bStrIsFloat = (SUCCEEDED(VariantChangeType(&vValue, &vValue, 0, VT_R8)) && sValue.Find('.') != -1);
if(bStrIsFloat)
{
AfxMes...
Objective-C : BOOL vs bool
...
199
From the definition in objc.h:
#if (TARGET_OS_IPHONE && __LP64__) || TARGET_OS_WATCH...
What does the restrict keyword mean in C++?
...commends it's usage when available:
restrict keyword
! New to 1999 ANSI/ISO C standard
! Not in C++ standard yet, but supported by many C++ compilers
! A hint only, so may do nothing and still be conforming
A restrict-qualified pointer (or reference)...
! ...
Why aren't variable-length arrays part of the C++ standard?
... And if you don't know the size beforehand, you will write unsafe code.
C99 VLAs could provide a small benefit of being able to create small arrays without wasting space or calling constructors for unused elements, but they will introduce rather large changes to the type system (you need to be abl...
What does the C++ standard state the size of int, long type to be?
...one of these de facto standards is legislated by the C standard (ISO/IEC 9899:1999), but all are permitted by it.
And, by definition, sizeof(char) is 1, notwithstanding the test in the Perl configure script.
Note that there were machines (Crays) where CHAR_BIT was much larger than 8. That meant, ...
pandas: filter rows of DataFrame with operator chaining
... A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
A B C D
d 1 3 9 6
If you want to chain methods, you can add your own mask method and use that one.
In [90]: def mask(df, key, value):
....: return df[df[key]...
How to print a number with commas as thousands separators in JavaScript
...ith commas as thousands separators. For example, I want to show the number 1234567 as "1,234,567". How would I go about doing this?
...
In Objective-C why should I check if self = [super init] is not nil?
... that if (self != nil) check is there, for proper operation of your class, 99.99% of the time you actually do need self to be non-nil.
Now, suppose, for whatever reason, [super init] did return nil, basically your check against nil is basically passing the buck up to the caller of your class, where...