Formatting text in C++: Old and new ways
mariusbancila.ro
Formatting text in C++: Old and new ways
1–10 of 73 posts
Re: Formatting text in C++: Old and new ways
#2 unsigned char str[]{3,4,5,6,0};
std::stringstream ss;
ss no, it wont. if you are on an old Windows with code page 437 then sure. but on any sane UTF-8 system, you're just going to get some binary data.
Re: Formatting text in C++: Old and new ways
#3It seems so trite, especially in 2023, but please don't use sprintf. It isn't safe in general. (Even snprintf is tricky.)
Re: Formatting text in C++: Old and new ways
#4unsigned char str[]{3,4,5,6,0}; std::stringstream ss; ss > The content of text will be "str=♥♦♣♠". no, it wont. if you are on an old Windows with code page 437 then sure. but on any sane UTF-8 system, you're just going to get some binary data. 1. https://wikipedia.org/wiki/Code_page_437
Thanks for finding this out as a codepage issue. The implementation of the operator<< will indeed call ostream::widen() to expand character into a locale dependent equivalent.
Re: Formatting text in C++: Old and new ways
#5It seems so trite, especially in 2023, but please don't use sprintf. It isn't safe in general. (Even snprintf is tricky.)
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Re: Formatting text in C++: Old and new ways
#6It seems so trite, especially in 2023, but please don't use sprintf. It isn't safe in general. (Even snprintf is tricky.)
YOLO
Re: Formatting text in C++: Old and new ways
#7Something else to consider is compile time versus runtime validation with formatting libraries, e.g. due to passing the wrong number or type of arguments. The Abseil str_format library does compile time validation for both when possible: https://abseil.io/docs/cpp/guides/format
Re: Formatting text in C++: Old and new ways
#8It seems so trite, especially in 2023, but please don't use sprintf. It isn't safe in general. (Even snprintf is tricky.)
saying "dont use" something isn't really actionable, unless you give a safe alternative.
Re: Formatting text in C++: Old and new ways
#9I find it disappointing that cpp20 still doesn't have a solution that is more convenient than good ol printf (except for memory safety).
Another example would be convenient list comprehension, convenient maps wihout juggling around with tuples, first(), second(), at()...
Re: Formatting text in C++: Old and new ways
#10I find it disappointing that cpp20 still doesn't have a solution that is more convenient than good ol printf (except for memory safety). Another example would be convenient list comprehension, convenient maps wihout juggling around with tuples, first(), second(), at()...
Maps have been improved quite a bit.
For example, if you have a std::map, you can iterate over it like this:
for (auto [s, n]: my_map) {
// s = string key, n = int value
}
if (my_map.contains(“foo”)) { /* do something * }
You can use initialization lists with them too:
std::map my_map = {
{ “one”, 1 },
{ “two”, 2 },
{ “three”, 3 }
};