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Meaning of 'const' last in a function declaration of a class?
... had the following extra method declaration:
class foobar {
...
const char* bar();
}
The method bar() is non-const and can only be accessed from non-const values.
void func1(const foobar& fb1, foobar& fb2) {
const char* v1 = fb1.bar(); // won't compile
const char* v2 = fb2.bar()...
How to get pixel data from a UIImage (Cocoa Touch) or CGImage (Core Graphics)?
... CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
unsigned char *rawData = (unsigned char*) calloc(height * width * 4, sizeof(unsigned char));
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
CGContextRef c...
How to read a single char from the console in Java (as the user types it)?
Is there an easy way to read a single char from the console as the user is typing it in Java? Is it possible? I've tried with these methods but they all wait for the user to press enter key:
...
What's “wrong” with C++ wchar_t and wstrings? What are some alternatives to wide characters?
...mmunity(particularly ##c++ on freenode) resent the use of wstrings and wchar_t , and their use in the windows api. What is exactly "wrong" with wchar_t and wstring , and if I want to support internationalization, what are some alternatives to wide characters?
...
Types in MySQL: BigInt(20) vs Int(20)
...E TABLE foo ( bar INT(20) ZEROFILL );
INSERT INTO foo (bar) VALUES (1234);
SELECT bar from foo;
+----------------------+
| bar |
+----------------------+
| 00000000000000001234 |
+----------------------+
It's a common source of confusion for MySQL users to see INT(20) and assume ...
What is a segmentation fault?
...hen you try to write to a portion of memory that was marked as read-only:
char *str = "Foo"; // Compiler marks the constant string as read-only
*str = 'b'; // Which means this is illegal and results in a segfault
Dangling pointer points to a thing that does not exist any more, like here:
char *p...
Is C++14 adding new keywords to C++?
...ch else namespace static_assert using
char enum new static_cast virtual
char16_t explicit noexcept struct void
char32_t export nullptr switch ...
Is gcc's __attribute__((packed)) / #pragma pack unsafe?
....h>
#include <stddef.h>
int main(void)
{
struct foo {
char c;
int x;
} __attribute__((packed));
struct foo arr[2] = { { 'a', 10 }, {'b', 20 } };
int *p0 = &arr[0].x;
int *p1 = &arr[1].x;
printf("sizeof(struct foo) = %d\n", (int)sizeof(str...
Read Excel File in Python
...ues for a given column
values = df['Arm_id'].values
#get a data frame with selected columns
FORMAT = ['Arm_id', 'DSPName', 'Pincode']
df_selected = df[FORMAT]
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How do I trim whitespace from a string?
... Hello ")
' Hello'
Also, note that str.strip() removes other whitespace characters as well (e.g. tabs and newlines). To remove only spaces, you can specify the character to remove as an argument to strip, i.e.:
>>> " Hello\n".strip(" ")
'Hello\n'
...