[clang-tidy] Use C++ using instead of C typedef

Found with modernize-use-using

Signed-off-by: Rosen Penev <rosenp@gmail.com>

src/builtin_string.cpp

@@ -1222,7 +1222,7 @@ static int string_sub(parser_t &parser, io_streams_t &streams, int argc, wchar_t
     int nsub = 0;
     arg_iterator_t aiter(argv, optind, streams);
     while (const wcstring *s = aiter.nextstr()) {
-        typedef wcstring::size_type size_type;
+        using size_type = wcstring::size_type;
         size_type pos = 0;
         size_type count = wcstring::npos;
         if (opts.start > 0) {

src/complete.cpp

@@ -124,7 +124,7 @@ typedef struct complete_entry_opt {
 static std::atomic<unsigned int> k_complete_order{0};
 
 /// Struct describing a command completion.
-typedef std::list<complete_entry_opt_t> option_list_t;
+using option_list_t = std::list<complete_entry_opt_t>;
 class completion_entry_t {
    public:
     /// List of all options.
@@ -166,7 +166,7 @@ struct equal_to<completion_entry_t> {
     }
 };
 }  // namespace std
-typedef std::unordered_set<completion_entry_t> completion_entry_set_t;
+using completion_entry_set_t = std::unordered_set<completion_entry_t>;
 static owning_lock<completion_entry_set_t> s_completion_set;
 
 /// Completion "wrapper" support. The map goes from wrapping-command to wrapped-command-list.

src/fish_indent.cpp

@@ -47,7 +47,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 #define SPACES_PER_INDENT 4
 
 // An indent_t represents an abstract indent depth. 2 means we are in a doubly-nested block, etc.
-typedef unsigned int indent_t;
+using indent_t = unsigned int;
 static bool dump_parse_tree = false;
 static int ret = 0;
 

src/highlight.cpp

@@ -774,7 +774,7 @@ class highlighter_t {
     // Working directory.
     const wcstring working_directory;
     // The resulting colors.
-    typedef std::vector<highlight_spec_t> color_array_t;
+    using color_array_t = std::vector<highlight_spec_t>;
     color_array_t color_array;
     // The parse tree of the buff.
     parse_node_tree_t parse_tree;

src/iothread.cpp

@@ -41,7 +41,7 @@
 static void iothread_service_main_thread_requests();
 static void iothread_service_result_queue();
 
-typedef std::function<void(void)> void_function_t;
+using void_function_t = std::function<void()>;
 
 struct work_request_t {
     void_function_t handler;

src/kill.cpp

@@ -15,7 +15,7 @@
 #include "fallback.h"  // IWYU pragma: keep
 
 /** Kill ring */
-typedef std::list<wcstring> kill_list_t;
+using kill_list_t = std::list<wcstring>;
 static kill_list_t kill_list;
 
 void kill_add(wcstring str) {

src/pager.cpp

@@ -20,9 +20,9 @@
 #include "screen.h"
 #include "wutil.h"  // IWYU pragma: keep
 
-typedef pager_t::comp_t comp_t;
-typedef std::vector<completion_t> completion_list_t;
-typedef std::vector<comp_t> comp_info_list_t;
+using comp_t = pager_t::comp_t;
+using completion_list_t = std::vector<completion_t>;
+using comp_info_list_t = std::vector<comp_t>;
 
 /// The minimum width (in characters) the terminal must to show completions at all.
 #define PAGER_MIN_WIDTH 16

src/parser_keywords.cpp

@@ -9,7 +9,7 @@
 #include "common.h"
 #include "fallback.h"  // IWYU pragma: keep
 
-typedef std::unordered_set<wcstring> string_set_t;
+using string_set_t = std::unordered_set<wcstring>;
 
 static const wcstring skip_keywords[]{
     L"else",

src/proc.cpp

@@ -290,7 +290,7 @@ io_chain_t job_t::all_io_redirections() const {
     return result;
 }
 
-typedef unsigned int process_generation_count_t;
+using process_generation_count_t = unsigned int;
 
 /// A list of pids/pgids that have been disowned. They are kept around until either they exit or
 /// we exit. Poll these from time-to-time to prevent zombie processes from happening (#5342).

src/tinyexpr.cpp

@@ -38,9 +38,9 @@
 
 // TODO: It would be nice not to rely on a typedef for this, especially one that can only do
 // functions with two args.
-typedef double (*te_fun2)(double, double);
-typedef double (*te_fun1)(double);
-typedef double (*te_fun0)();
+using te_fun2 = double (*)(double, double);
+using te_fun1 = double (*)(double);
+using te_fun0 = double (*)();
 
 enum {
     TE_CONSTANT = 0,

src/utf8.cpp

@@ -33,10 +33,10 @@
 #define _BOM 0xfeff
 
 // We can tweak the following typedef to allow us to simulate Windows-style 16 bit wchar's on Unix.
-typedef wchar_t utf8_wchar_t;
+using utf8_wchar_t = wchar_t;
 #define UTF8_WCHAR_MAX (wchar_t) std::numeric_limits<utf8_wchar_t>::max()
 
-typedef std::basic_string<utf8_wchar_t> utf8_wstring_t;
+using utf8_wstring_t = std::basic_string<utf8_wchar_t>;
 
 static size_t utf8_to_wchar_internal(const char *in, size_t insize, utf8_wstring_t *out_string,
                                      int flags);

src/wcstringutil.cpp

@@ -7,7 +7,7 @@
 
 #include "common.h"
 
-typedef wcstring::size_type size_type;
+using size_type = wcstring::size_type;
 
 wcstring_range wcstring_tok(wcstring &str, const wcstring &needle, wcstring_range last) {
     size_type pos = last.second == wcstring::npos ? wcstring::npos : last.first;

src/wutil.cpp

@@ -31,7 +31,7 @@
 #include "flog.h"
 #include "wutil.h"  // IWYU pragma: keep
 
-typedef std::string cstring;
+using cstring = std::string;
 
 const file_id_t kInvalidFileID = {static_cast<dev_t>(-1LL),
                                   static_cast<ino_t>(-1LL),