In this post, we will see how to resolve Is flat_map an STL container? Question: In the current draft of C++23s flat_map design, the type flat_map::reference is defined as pair<const key_type&, mapped_type&>, i.e. it is not a reference to flat_map::value_type ...

In this post, we will see how to resolve What is a bfloat16_t in the C++23 standard? Question: Cppreference documents that stdfloat includes 5 new types: float16_t, float32_t, float64_t, float128_t and bfloat16_t. While the first 4 types are self-explanatory (a ...

Question: Motivation: In the implementation of P0288 std::move_only_function, I’d like to write a non-allocating special case for conversion from move_only_function<int() noexcept> to move_only_function<int()>: I want to write, like, I wanted to implement that type trait like this: but no vendor ...

Question: They serve basically the same purpose, why do they have differences, specifically no column in stacktrace_entry, or not even share the same class? Answer: They serve basically the same purpose, They do not serve the same purpose: if anything ...

Question: In C++23, monadic operations in std::optional was adopted, and later on std::expected. Why were monadic operations like and_then, transform, and or_else not included in the main paper? Answer: The std::expected proposal is very old. The adopted revision is P0323R12, ...

Question: From §4.2.7 of the proposal http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0847r7.html#pathological-cases It said that: These are even more unlikely to be actually useful code. In this example, B is neither convertible to A nor int, so neither of these functions is even invocable using ...

Question: There used to be a paragraph in the standard which stated that the names of a namespace-scope friend functions of a class template specialization are not visible during an ordinary lookup unless explicitly declared at namespace scope. Such names ...