[348] - Did you know that C++26 changed arithmetic overloads of std::…

…to_string and std::to_wstring to use std::format?

README.md

@@ -12,6 +12,7 @@
 
 ### Tips
 
+* [[348]](/tips/348.md) - Did you know that C++26 changed arithmetic overloads of std::to_string and std::to_wstring to use std::format?
 * [[347]](/tips/347.md) - Did you know that C++26 added more constexpr for `<cmath>` and `<complex>`?
 * [[346]](/tips/346.md) - Did you know that C++26 added testing for success or failure of `<charconv>` functions?
 * [[345]](/tips/345.md) - Did you know that C++26 allows constexpr cast from `void*`?
@@ -124,7 +125,7 @@
 * [[238]](/tips/238.md) - Did you know that Circle Meta-model allows for applying `normal` STL for operations on @meta types?
 * [[237]](/tips/237.md) - Did you know about C++2X proposal for the Circle Meta-model for compilation-time meta-progr
 * [[236]](/tips/236.md) - Did you know about `__builtin_dump_struct` clang-extension which can nicely print a struct?
-* [[235]](/tips/235.md) - Did you know that C++20 `[[no_unique_address]]` can be used to implement lazy/fast/memory efficient 
+* [[235]](/tips/235.md) - Did you know that C++20 `[[no_unique_address]]` can be used to implement lazy/fast/memory efficient
 * [[234]](/tips/234.md) - Did you know about function-try-block and that exceptions caught inside that block are implicitly
 * [[233]](/tips/233.md) - Did you know that C++20 made `typename` more optional?
 * [[232]](/tips/232.md) - Did you know that different overloads can have different specifiers?

feed.template.xml

@@ -9,4 +9,3 @@
         <!-- START FEED -->
     </channel>
 </rss>
-

tips/347.md

@@ -34,5 +34,31 @@ static_assert(123 == 123_number);
 </p></details>
 
 </p></details><details><summary>Solutions</summary><p>
+
+```cpp
+template <char... Cs>
+[[nodiscard]] constexpr auto operator""_number() {
+    return []<auto... Is, class T = int>(std::index_sequence<Is...>) {
+        return std::integral_constant<
+            T, (((Cs - '0') * T(std::pow(T(10), sizeof...(Is) - Is - 1))) +
+                ...)>{};
+    }
+    (std::make_index_sequence<sizeof...(Cs)>{});
+}
+```
+
+> https://godbolt.org/z/qMvKcc8ff
+
+
+```cpp
+template <char... Cs>
+[[nodiscard]] constexpr auto operator""_number() {
+    int result = 0;
+    ((result = result * 10 + (Cs - '0')), ...);
+    return result;
+}
+```
+
 > https://godbolt.org/z/7vs1d51no
+
 </p></details>

tips/348.md

@@ -0,0 +1,46 @@
+<details open><summary>Info</summary><p>
+
+* **Did you know that C++26 changed arithmetic overloads of std::to_string and std::to_wstring to use std::format?**
+
+  * https://wg21.link/P2587
+
+</p></details><details open><summary>Example</summary><p>
+
+```cpp
+int main() {
+    setlocale(LC_ALL, "C");
+    std::cout << std::to_string(42); // prints 42
+    std::cout << std::to_string(.42); // prints 0.42
+    std::cout << std::to_string(-1e7); // prints -1e+07
+}
+```
+
+> https://godbolt.org/z/a7xMEq336
+
+</p></details><details open><summary>Puzzle</summary><p>
+
+* **Can you add required `locale` to match expectations?**
+
+```cpp
+int main() {
+    using namespace boost::ut;
+    using std::literals::string_literals::operator""s;
+
+    "locale.to_string (all.us)"_test = [] {
+        // TODO
+        expect("-1e+07"s == std::to_string(-1e7));
+    };
+
+    "locale.to_string (numeric.eu)"_test = [] {
+        // TODO
+        expect("1,23"s == std::to_string(1.23));
+    };
+}
+```
+
+> https://godbolt.org/z/jocqoM7xd
+
+</p></details>
+
+</p></details><details><summary>Solutions</summary><p>
+</p></details>