Questions tagged [function-signature]
80 questions
85
votes
4 answers
Is char *envp[] as a third argument to main() portable
In order to get an environment variable in a C program, one could use the following:
getenv()
extern char **environ;
But other than the above mentioned, is using char *envp[] as a third argument to main() to get the environment variables…
Sangeeth Saravanaraj
- 16,027
- 21
- 69
- 98
42
votes
7 answers
Is there a tool that generates P/Invoke signatures for arbitrary unmanaged DLL?
I stumbled upon a tool that generates P/Invoke signatures for Microsoft's own unmanaged DLLs: PInvoke Interop Assistant
Is there a similar tool that will generate P/Invoke signatures for third-party unmanaged DLLs?
Alternately, any way to feed a…
GregC
- 7,737
- 2
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37
votes
5 answers
Required parameter $xxx follows optional parameter $yyy
Deprecated: Required parameter $xxx follows optional parameter $yyy in...
Since upgrading to PHP 8.0 this error is thrown when running code like this:
function test_function(int $var1 = 2, int $var2) {
return $var1 / $var2;
}
This has worked…
miken32
- 42,008
- 16
- 111
- 154
35
votes
4 answers
How to compare the signature of two functions?
Is there a way to check if two functions have the same signature? For example:
int funA (int a, int b);
int funB (int a, int b);
float funC (int a, int b);
int funD (float a, int b);
In this example, funA and funB is the only combination of…
pallagommosa
- 558
- 7
- 15
35
votes
2 answers
Function pointers with default parameters in C++
How does C++ handle function pointers in relation to functions with defaulted parameters?
If I have:
void foo(int i, float f = 0.0f);
void bar(int i, float f);
void (*func_ptr1)(int);
void (*func_ptr2)(int, float);
void (*func_ptr3)(int, float =…
user308926
- 351
- 3
- 3
19
votes
4 answers
What's the meaning of multiple const qualifiers?
Code:
const char* const* const* foo(int bar);
I've seen double consts before which prevent the modification of the pointer too. First time i've seen triple const in my life. Wondering what its use is.
Learath2
- 20,023
- 2
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- 30
18
votes
1 answer
How to define template function within template class in *.inl file
I write template declaration in *.hpp file and their "definition" in *.inl file linked from *.hpp
just like this:
//*.hpp
template
class SomeClass
{
public:
void someMethod();
};
//*.inl
template
relaxxx
- 7,566
- 8
- 37
- 64
15
votes
4 answers
Can an unnamed parameter of function have a default value?
Is the following code legal in C++?
void f(void* = 0)
{}
int main()
{
f();
}
Which page of the C++ standard states that this usage is legal?
xmllmx
- 39,765
- 26
- 162
- 323
13
votes
2 answers
Why is return type before the function name?
The new C++11 standard adds a new function declaration syntax with a trailing return type:
// Usual declaration
int foo();
// New declaration
auto foo() -> int;
This syntax has the advantage of letting the return type be deduced, as…
authchir
- 1,605
- 14
- 26
11
votes
4 answers
Ternary operator and function signature
Let's say I have a C++ class with two functions like
class MyClass
{
bool Foo(int val);
bool Foo(string val);
}
Is it possible to use the ternary operator like this
MyClassInstance->Foo(booleanValue?24:"a string");
and have a different…
Yannick Blondeau
- 9,465
- 8
- 52
- 74
10
votes
2 answers
Any way to find all possible kwargs for a function in python from cli?
Is there a way to discover the potential keyword arguments for a function in python from the command line? without looking at the source or docs. Sometimes the source is to c lib even that isn't visible
Riz
- 1,055
- 11
- 18
9
votes
4 answers
How to declare two functions taking each other's signature as argument?
Is it possible to emulate something like this:
typedef boost::function B;
typedef boost::function A;
The main goal is to be able to write code like this (in pseudo-c++):
void a_(B b) {
// ...
b(a_);
}
void b_(A a) {
// ...
…
abyss.7
- 13,882
- 11
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- 100
9
votes
2 answers
TypeScript - check if object's property is a function with given signature
I have a function that gets a property from an object.
// Utils.ts
export function getProperty(obj: T, key: string): T[K] {
if (key in obj) { return obj[key as K]; }
throw new Error(`Invalid object member…
Forseti
- 2,587
- 6
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- 32
9
votes
3 answers
Whats the pythonic way to handle empty *args when creating a set?
Defining a function,
MyFunction(argument, *args):
[do something to argument[arg] for arg in *args]
if *args is empty, the function doesn't do anything, but I want to make the default behavior 'use the entire set if length of *args == 0'
def…
justin cress
- 1,745
- 5
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- 35
7
votes
0 answers
Remove function argument after setting it to a value with functools.partial
I would like to use functools.partial to set a certain argument to a constant and at the same time remove the argument altogether.
Let me explain it using a simple example.
from functools import partial
def f(a, b):
return a * b
g = partial(f,…
johnbaltis
- 1,413
- 4
- 14
- 26