https://github.com/huaiminnotsleepyet/named_args
A header-only library providing named arguments for C++ 17.
https://github.com/huaiminnotsleepyet/named_args
Last synced: 3 months ago
JSON representation
A header-only library providing named arguments for C++ 17.
- Host: GitHub
- URL: https://github.com/huaiminnotsleepyet/named_args
- Owner: HuaiminNotSleepYet
- License: mit
- Created: 2024-10-16T11:23:49.000Z (7 months ago)
- Default Branch: main
- Last Pushed: 2024-10-20T08:55:36.000Z (7 months ago)
- Last Synced: 2025-01-11T13:27:38.246Z (4 months ago)
- Language: C++
- Homepage:
- Size: 4.88 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
README
# named_args
A header-only library providing named arguments for C++ 17.
---
## Usage
Declare a name by `named_arg`:
```cpp
named_arg(a)
named_arg(b)
named_arg(c)
named_arg(d)
```
Declare named parameters by `named_arg_list`. The method must have a parameter pack called `args`:
```cpp
template
void foo(Args&&... args)
{
using named_args::optional;
using named_args::required;
named_arg_list
(
int&, a, required,
int , b, optional,
int , c, 0
)
// This will create 3 type aliases:
// using a_t = int&;
// using b_t = std::optional;
// using c_t = int;
//
// and 3 variables:
// a_t a
// b_t b
// c_t c
std::cout << "a: " << a << " b: ";
if (b)
std::cout << *b;
else
std::cout << '_';
std::cout << " c: " << c << '\n';
++a;
}
```
Example:
```cpp
int main()
{
using named_args::names::a;
using named_args::names::b;
using named_args::names::c;
using named_args::names::d;
int val = 0;
foo(a=val, b=4, c=5);
foo(c=5, b=4, a=val);
foo(a=val);
// foo(b=0, c=1);
// ^ static assertion failed: missing required arg: 'a'.
// foo(a=val, c=new int);
// ^ static assertion failed: cannot convert the type of arg 'c' to 'int'.
// foo(a=val, b=4, c=5, d=6);
// ^ static assertion failed: additional arg in the input.
std::cout << "val: " << val << std::endl;
return 0;
}
```
Outputs:
```
a: 0 b: 4 c: 5
a: 1 b: 4 c: 5
a: 2 b: _ c: 0
val: 3
```
## Related
- [Strong types for strong interfaces](https://www.fluentcpp.com/2016/12/08/strong-types-for-strong-interfaces/)
- [NamedType](https://github.com/joboccara/NamedType): Implementation of strong types in C++