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How to make my custom type to work with “range-based for loops”?
... return false;
}
};
live example of this.
Minimal test code is:
struct cstring {
const char* ptr = 0;
const char* begin() const { return ptr?ptr:""; }// return empty string if we are null
null_sentinal_t end() const { return {}; }
};
cstring str{"abc"};
for (char c : str) {
std::cout &...
Create objective-c class instance by name?
...
id object = [[NSClassFromString(@"NameofClass") alloc] init];
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How do I sort unicode strings alphabetically in Python?
...rary. It is pretty easy.
# python2.5 code below
# corpus is our unicode() strings collection as a list
corpus = [u"Art", u"Älg", u"Ved", u"Wasa"]
import locale
# this reads the environment and inits the right locale
locale.setlocale(locale.LC_ALL, "")
# alternatively, (but it's bad to hardcode)
#...
Replace non-numeric with empty string
...et passed "(913)-444-5555" or anything else, is there a quick way to run a string through some kind of special replace function that I can pass it a set of characters to allow?
...
Difference between const & const volatile
...be the status register for a serial port. Various bits will indicate if a character is waiting to be read or if the transmit register is ready to accept a new character (ie., - it's empty). Each read of this status register could result in a different value depending on what else has occurred in t...
Can we have functions inside functions in C++?
... which can be called just like a function
auto print_message = [](std::string message)
{
std::cout << message << "\n";
};
// Prints "Hello!" 10 times
for(int i = 0; i < 10; i++) {
print_message("Hello!");
}
}
Lambdas can also modify local...
How to get the type of a variable in MATLAB?
...
for conditionals: if ( string(class(b)) == 'double' ) fprintf(1, 'b is double'); end
– khaverim
Apr 16 at 18:09
add a comme...
Integer to hex string in C++
How do I convert an integer to a hex string in C++ ?
17 Answers
17
...
differentiate null=True, blank=True in django
...ngo are never saved as NULL. Blank values are stored in the DB as an empty string ('').
A few examples:
models.DateTimeField(blank=True) # raises IntegrityError if blank
models.DateTimeField(null=True) # NULL allowed, but must be filled out in a form
Obviously, Those two options don't make logi...
MySQL stored procedure vs function, which would I use when?
...ons and triggers cannot use Dynamic SQL (where you construct statements as strings and then execute them). (Dynamic SQL in MySQL stored routines)
Some more interesting differences between FUNCTION and STORED PROCEDURE:
(This point is copied from a blogpost.)
Stored procedure is precompiled execu...