Skip to content

[2026-06 LWG Motion 3] P3798R1 The unexpected in std::expected #9127

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
eisenwave wants to merge 1 commit into
base: main
Choose a base branch
from
+31 −1
Open

[2026-06 LWG Motion 3] P3798R1 The unexpected in std::expected #9127

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion source/support.tex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -674,7 +674,7 @@
#define @\defnlibxname{cpp_lib_exception_ptr_cast}@ 202603L // also in \libheader{exception}
#define @\defnlibxname{cpp_lib_exchange_function}@ 201304L // freestanding, also in \libheader{utility}
#define @\defnlibxname{cpp_lib_execution}@ 201902L // also in \libheader{execution}
#define @\defnlibxname{cpp_lib_expected}@ 202211L // also in \libheader{expected}
#define @\defnlibxname{cpp_lib_expected}@ 202606L // also in \libheader{expected}
#define @\defnlibxname{cpp_lib_filesystem}@ 201703L // also in \libheader{filesystem}
#define @\defnlibxname{cpp_lib_flat_map}@ 202511L // also in \libheader{flat_map}
#define @\defnlibxname{cpp_lib_flat_set}@ 202511L // also in \libheader{flat_set}
Expand Down
30 changes: 30 additions & 0 deletions source/utilities.tex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8524,6 +8524,7 @@
constexpr T&& operator*() && noexcept;
constexpr explicit operator bool() const noexcept;
constexpr bool has_value() const noexcept;
constexpr bool has_error() const noexcept;
constexpr const T& value() const &; // freestanding-deleted
constexpr T& value() &; // freestanding-deleted
constexpr const T&& value() const &&; // freestanding-deleted
Expand Down Expand Up @@ -9417,6 +9418,20 @@
\exposid{has_val}.
\end{itemdescr}

\indexlibrarymember{has_error}{expected}%
\begin{itemdecl}
constexpr bool has_error() const noexcept;
\end{itemdecl}

\begin{itemdescr}
\pnum
\effects
Equivalent to:
\begin{codeblock}
return !has_value();
\end{codeblock}
\end{itemdescr}

\indexlibrarymember{value}{expected}%
\begin{itemdecl}
constexpr const T& value() const &;
Expand Down Expand Up @@ -9943,6 +9958,7 @@
// \ref{expected.void.obs}, observers
constexpr explicit operator bool() const noexcept;
constexpr bool has_value() const noexcept;
constexpr bool has_error() const noexcept;
constexpr void operator*() const noexcept;
constexpr void value() const &; // freestanding-deleted
constexpr void value() &&; // freestanding-deleted
Expand Down Expand Up @@ -10445,6 +10461,20 @@
\exposid{has_val}.
\end{itemdescr}

\indexlibrarymember{has_error}{expected<void>}%
\begin{itemdecl}
constexpr bool has_error() const noexcept;
\end{itemdecl}

\begin{itemdescr}
\pnum
\effects
Equivalent to:
\begin{codeblock}
return !has_value();
\end{codeblock}
\end{itemdescr}

\indexlibrarymember{operator*}{expected<void>}%
\begin{itemdecl}
constexpr void operator*() const noexcept;
Expand Down
Loading