gdb: Replace gdb::optional with std::optional

Since GDB now requires C++17, we don't need the internally maintained
gdb::optional implementation.  This patch does the following replacing:
  - gdb::optional -> std::optional
  - gdb::in_place -> std::in_place
  - #include "gdbsupport/gdb_optional.h" -> #include <optional>

This change has mostly been done automatically.  One exception is
gdbsupport/thread-pool.* which did not use the gdb:: prefix as it
already lives in the gdb namespace.

Change-Id: I19a92fa03e89637bab136c72e34fd351524f65e9
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Pedro Alves <pedro@palves.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index fd93e5b..cb9ff55 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -655,12 +655,12 @@ show_script_ext_mode (struct ui_file *file, int from_tty,
    If SEARCH_PATH is non-zero, and the file isn't found in cwd,
    search for it in the source search path.  */
 
-gdb::optional<open_script>
+std::optional<open_script>
 find_and_open_script (const char *script_file, int search_path)
 {
   int fd;
   openp_flags search_flags = OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH;
-  gdb::optional<open_script> opened;
+  std::optional<open_script> opened;
 
   gdb::unique_xmalloc_ptr<char> file (tilde_expand (script_file));
 
@@ -742,7 +742,7 @@ source_script_with_search (const char *file, int from_tty, int search_path)
   if (file == NULL || *file == 0)
     error (_("source command requires file name of file to source."));
 
-  gdb::optional<open_script> opened = find_and_open_script (file, search_path);
+  std::optional<open_script> opened = find_and_open_script (file, search_path);
   if (!opened)
     {
       /* The script wasn't found, or was otherwise inaccessible.