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Is gcc 4.8 or earlier buggy about regular expressions?
... highly experimental, tracking early C++0x drafts and being made available for people to experiment with. That allowed people to find problems and give feedback to the standard committee before the standard was finalised. At the time lots of people were grateful to have had access to bleeding edge f...
Delete column from pandas DataFrame
...en a column is to be removed, the DataFrame needs to have its own handling for "how to do it". In the case of del df[name], it gets translated to df.__delitem__(name) which is a method that DataFrame can implement and modify to its needs. In the case of del df.name, the member variable gets removed ...
What's the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__?
...nly use __FUNCTION__ if you are using a compiler that does not support it (for example, Visual C++, which does not support C99 and does not yet support all of C++0x, does not provide __func__).
__PRETTY_FUNCTION__ is a gcc extension that is mostly the same as __FUNCTION__, except that for C++ functi...
What is the difference between __dirname and ./ in node.js?
...ide require is always relative to the file containing the call to require.
For example...
Let's say your directory structure is
/dir1
/dir2
pathtest.js
and pathtest.js contains
var path = require("path");
console.log(". = %s", path.resolve("."));
console.log("__dirname = %s", path.resolve(__d...
What is the preferred/idiomatic way to insert into a map?
...r functions are not functionally equivalent :
The operator[] will search for the key, insert a default constructed value if not found, and return a reference to which you assign a value. Obviously, this can be inefficient if the mapped_type can benefit from being directly initialized instead of de...
Elegant Python function to convert CamelCase to snake_case?
...name
If you do this many times and the above is slow, compile the regex beforehand:
pattern = re.compile(r'(?<!^)(?=[A-Z])')
name = pattern.sub('_', name).lower()
To handle more advanced cases specially (this is not reversible anymore):
def camel_to_snake(name):
name = re.sub('(.)([A-Z][a-z]+...
Are there legitimate uses for JavaScript's “with” statement?
...laring a closure in a loop is a common task where this can lead to errors:
for (var i=0; i<3; ++i)
{
var num = i;
setTimeout(function() { alert(num); }, 10);
}
Because the for loop does not introduce a new scope, the same num - with a value of 2 - will be shared by all three functions.
A n...
How to find the JVM version from a program?
... Java Runtime Environment version date, in ISO-8601 YYYY-MM-DD format, which may be interpreted as a LocalDate
java.vendor "Oracle Corporation" "Oracle Corporation" "Sun Microsystems Inc." Java Runt...
Convert a String In C++ To Upper Case
...
This appears to perform extremely badly with g++ 5.2 -O3, and Boost 1.58 (like 30x worse than calling glibc's toupper in a loop.) There's a dynamic_cast of the locale that doesn't get hoisted out of the per-char loop. See my answer. On the p...
Why do people use __(double underscore) so much in C++
...dations :
The use of two underscores (`__') in identifiers is reserved for the compiler's internal use according to the ANSI-C standard.
Underscores (`_') are often used in names of library functions (such as "_main" and "_exit"). In order to avoid collisions, do not begin an identifier wit...