Merge pull request #3628 from ziglang/as-builtin

implement `@as` builtin and fix result location semantics with regards to type coercion

1 files changed, 94 insertions, 94 deletions

diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index a7dedefb43..618a21f456 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -46,22 +46,22 @@ pub fn getErrno(r: usize) u12 {
 
 pub fn dup2(old: i32, new: i32) usize {
     if (@hasDecl(@This(), "SYS_dup2")) {
-        return syscall2(SYS_dup2, @bitCast(usize, isize(old)), @bitCast(usize, isize(new)));
+        return syscall2(SYS_dup2, @bitCast(usize, @as(isize, old)), @bitCast(usize, @as(isize, new)));
     } else {
         if (old == new) {
             if (std.debug.runtime_safety) {
-                const rc = syscall2(SYS_fcntl, @bitCast(usize, isize(old)), F_GETFD);
+                const rc = syscall2(SYS_fcntl, @bitCast(usize, @as(isize, old)), F_GETFD);
                 if (@bitCast(isize, rc) < 0) return rc;
             }
             return @intCast(usize, old);
         } else {
-            return syscall3(SYS_dup3, @bitCast(usize, isize(old)), @bitCast(usize, isize(new)), 0);
+            return syscall3(SYS_dup3, @bitCast(usize, @as(isize, old)), @bitCast(usize, @as(isize, new)), 0);
         }
     }
 }
 
 pub fn dup3(old: i32, new: i32, flags: u32) usize {
-    return syscall3(SYS_dup3, @bitCast(usize, isize(old)), @bitCast(usize, isize(new)), flags);
+    return syscall3(SYS_dup3, @bitCast(usize, @as(isize, old)), @bitCast(usize, @as(isize, new)), flags);
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -102,7 +102,7 @@ pub fn futimens(fd: i32, times: *const [2]timespec) usize {
 
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn utimensat(dirfd: i32, path: ?[*]const u8, times: *const [2]timespec, flags: u32) usize {
-    return syscall4(SYS_utimensat, @bitCast(usize, isize(dirfd)), @ptrToInt(path), @ptrToInt(times), flags);
+    return syscall4(SYS_utimensat, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), @ptrToInt(times), flags);
 }
 
 pub fn futex_wait(uaddr: *const i32, futex_op: u32, val: i32, timeout: ?*timespec) usize {
@@ -120,7 +120,7 @@ pub fn getcwd(buf: [*]u8, size: usize) usize {
 pub fn getdents(fd: i32, dirp: [*]u8, len: usize) usize {
     return syscall3(
         SYS_getdents,
-        @bitCast(usize, isize(fd)),
+        @bitCast(usize, @as(isize, fd)),
         @ptrToInt(dirp),
         std.math.min(len, maxInt(c_int)),
     );
@@ -129,7 +129,7 @@ pub fn getdents(fd: i32, dirp: [*]u8, len: usize) usize {
 pub fn getdents64(fd: i32, dirp: [*]u8, len: usize) usize {
     return syscall3(
         SYS_getdents64,
-        @bitCast(usize, isize(fd)),
+        @bitCast(usize, @as(isize, fd)),
         @ptrToInt(dirp),
         std.math.min(len, maxInt(c_int)),
     );
@@ -140,11 +140,11 @@ pub fn inotify_init1(flags: u32) usize {
 }
 
 pub fn inotify_add_watch(fd: i32, pathname: [*]const u8, mask: u32) usize {
-    return syscall3(SYS_inotify_add_watch, @bitCast(usize, isize(fd)), @ptrToInt(pathname), mask);
+    return syscall3(SYS_inotify_add_watch, @bitCast(usize, @as(isize, fd)), @ptrToInt(pathname), mask);
 }
 
 pub fn inotify_rm_watch(fd: i32, wd: i32) usize {
-    return syscall2(SYS_inotify_rm_watch, @bitCast(usize, isize(fd)), @bitCast(usize, isize(wd)));
+    return syscall2(SYS_inotify_rm_watch, @bitCast(usize, @as(isize, fd)), @bitCast(usize, @as(isize, wd)));
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -152,13 +152,13 @@ pub fn readlink(noalias path: [*]const u8, noalias buf_ptr: [*]u8, buf_len: usiz
     if (@hasDecl(@This(), "SYS_readlink")) {
         return syscall3(SYS_readlink, @ptrToInt(path), @ptrToInt(buf_ptr), buf_len);
     } else {
-        return syscall4(SYS_readlinkat, @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(path), @ptrToInt(buf_ptr), buf_len);
+        return syscall4(SYS_readlinkat, @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(path), @ptrToInt(buf_ptr), buf_len);
     }
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn readlinkat(dirfd: i32, noalias path: [*]const u8, noalias buf_ptr: [*]u8, buf_len: usize) usize {
-    return syscall4(SYS_readlinkat, @bitCast(usize, isize(dirfd)), @ptrToInt(path), @ptrToInt(buf_ptr), buf_len);
+    return syscall4(SYS_readlinkat, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), @ptrToInt(buf_ptr), buf_len);
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -166,13 +166,13 @@ pub fn mkdir(path: [*]const u8, mode: u32) usize {
     if (@hasDecl(@This(), "SYS_mkdir")) {
         return syscall2(SYS_mkdir, @ptrToInt(path), mode);
     } else {
-        return syscall3(SYS_mkdirat, @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(path), mode);
+        return syscall3(SYS_mkdirat, @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(path), mode);
     }
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn mkdirat(dirfd: i32, path: [*]const u8, mode: u32) usize {
-    return syscall3(SYS_mkdirat, @bitCast(usize, isize(dirfd)), @ptrToInt(path), mode);
+    return syscall3(SYS_mkdirat, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), mode);
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -194,7 +194,7 @@ pub fn mmap(address: ?[*]u8, length: usize, prot: usize, flags: u32, fd: i32, of
     if (@hasDecl(@This(), "SYS_mmap2")) {
         // Make sure the offset is also specified in multiples of page size
         if ((offset & (MMAP2_UNIT - 1)) != 0)
-            return @bitCast(usize, isize(-EINVAL));
+            return @bitCast(usize, @as(isize, -EINVAL));
 
         return syscall6(
             SYS_mmap2,
@@ -202,7 +202,7 @@ pub fn mmap(address: ?[*]u8, length: usize, prot: usize, flags: u32, fd: i32, of
             length,
             prot,
             flags,
-            @bitCast(usize, isize(fd)),
+            @bitCast(usize, @as(isize, fd)),
             @truncate(usize, offset / MMAP2_UNIT),
         );
     } else {
@@ -212,7 +212,7 @@ pub fn mmap(address: ?[*]u8, length: usize, prot: usize, flags: u32, fd: i32, of
             length,
             prot,
             flags,
-            @bitCast(usize, isize(fd)),
+            @bitCast(usize, @as(isize, fd)),
             offset,
         );
     }
@@ -249,13 +249,13 @@ pub fn poll(fds: [*]pollfd, n: nfds_t, timeout: i32) usize {
 }
 
 pub fn read(fd: i32, buf: [*]u8, count: usize) usize {
-    return syscall3(SYS_read, @bitCast(usize, isize(fd)), @ptrToInt(buf), count);
+    return syscall3(SYS_read, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), count);
 }
 
 pub fn preadv(fd: i32, iov: [*]const iovec, count: usize, offset: u64) usize {
     return syscall5(
         SYS_preadv,
-        @bitCast(usize, isize(fd)),
+        @bitCast(usize, @as(isize, fd)),
         @ptrToInt(iov),
         count,
         @truncate(usize, offset),
@@ -266,7 +266,7 @@ pub fn preadv(fd: i32, iov: [*]const iovec, count: usize, offset: u64) usize {
 pub fn preadv2(fd: i32, iov: [*]const iovec, count: usize, offset: u64, flags: kernel_rwf) usize {
     return syscall6(
         SYS_preadv2,
-        @bitCast(usize, isize(fd)),
+        @bitCast(usize, @as(isize, fd)),
         @ptrToInt(iov),
         count,
         @truncate(usize, offset),
@@ -276,17 +276,17 @@ pub fn preadv2(fd: i32, iov: [*]const iovec, count: usize, offset: u64, flags: k
 }
 
 pub fn readv(fd: i32, iov: [*]const iovec, count: usize) usize {
-    return syscall3(SYS_readv, @bitCast(usize, isize(fd)), @ptrToInt(iov), count);
+    return syscall3(SYS_readv, @bitCast(usize, @as(isize, fd)), @ptrToInt(iov), count);
 }
 
 pub fn writev(fd: i32, iov: [*]const iovec_const, count: usize) usize {
-    return syscall3(SYS_writev, @bitCast(usize, isize(fd)), @ptrToInt(iov), count);
+    return syscall3(SYS_writev, @bitCast(usize, @as(isize, fd)), @ptrToInt(iov), count);
 }
 
 pub fn pwritev(fd: i32, iov: [*]const iovec_const, count: usize, offset: u64) usize {
     return syscall5(
         SYS_pwritev,
-        @bitCast(usize, isize(fd)),
+        @bitCast(usize, @as(isize, fd)),
         @ptrToInt(iov),
         count,
         @truncate(usize, offset),
@@ -297,7 +297,7 @@ pub fn pwritev(fd: i32, iov: [*]const iovec_const, count: usize, offset: u64) us
 pub fn pwritev2(fd: i32, iov: [*]const iovec_const, count: usize, offset: u64, flags: kernel_rwf) usize {
     return syscall6(
         SYS_pwritev2,
-        @bitCast(usize, isize(fd)),
+        @bitCast(usize, @as(isize, fd)),
         @ptrToInt(iov),
         count,
         @truncate(usize, offset),
@@ -311,7 +311,7 @@ pub fn rmdir(path: [*]const u8) usize {
     if (@hasDecl(@This(), "SYS_rmdir")) {
         return syscall1(SYS_rmdir, @ptrToInt(path));
     } else {
-        return syscall3(SYS_unlinkat, @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(path), AT_REMOVEDIR);
+        return syscall3(SYS_unlinkat, @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(path), AT_REMOVEDIR);
     }
 }
 
@@ -320,18 +320,18 @@ pub fn symlink(existing: [*]const u8, new: [*]const u8) usize {
     if (@hasDecl(@This(), "SYS_symlink")) {
         return syscall2(SYS_symlink, @ptrToInt(existing), @ptrToInt(new));
     } else {
-        return syscall3(SYS_symlinkat, @ptrToInt(existing), @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(new));
+        return syscall3(SYS_symlinkat, @ptrToInt(existing), @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(new));
     }
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn symlinkat(existing: [*]const u8, newfd: i32, newpath: [*]const u8) usize {
-    return syscall3(SYS_symlinkat, @ptrToInt(existing), @bitCast(usize, isize(newfd)), @ptrToInt(newpath));
+    return syscall3(SYS_symlinkat, @ptrToInt(existing), @bitCast(usize, @as(isize, newfd)), @ptrToInt(newpath));
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn pread(fd: i32, buf: [*]u8, count: usize, offset: usize) usize {
-    return syscall4(SYS_pread, @bitCast(usize, isize(fd)), @ptrToInt(buf), count, offset);
+    return syscall4(SYS_pread, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), count, offset);
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -339,13 +339,13 @@ pub fn access(path: [*]const u8, mode: u32) usize {
     if (@hasDecl(@This(), "SYS_access")) {
         return syscall2(SYS_access, @ptrToInt(path), mode);
     } else {
-        return syscall4(SYS_faccessat, @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(path), mode, 0);
+        return syscall4(SYS_faccessat, @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(path), mode, 0);
     }
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn faccessat(dirfd: i32, path: [*]const u8, mode: u32, flags: u32) usize {
-    return syscall4(SYS_faccessat, @bitCast(usize, isize(dirfd)), @ptrToInt(path), mode, flags);
+    return syscall4(SYS_faccessat, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), mode, flags);
 }
 
 pub fn pipe(fd: *[2]i32) usize {
@@ -363,11 +363,11 @@ pub fn pipe2(fd: *[2]i32, flags: u32) usize {
 }
 
 pub fn write(fd: i32, buf: [*]const u8, count: usize) usize {
-    return syscall3(SYS_write, @bitCast(usize, isize(fd)), @ptrToInt(buf), count);
+    return syscall3(SYS_write, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), count);
 }
 
 pub fn pwrite(fd: i32, buf: [*]const u8, count: usize, offset: usize) usize {
-    return syscall4(SYS_pwrite, @bitCast(usize, isize(fd)), @ptrToInt(buf), count, offset);
+    return syscall4(SYS_pwrite, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), count, offset);
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -375,9 +375,9 @@ pub fn rename(old: [*]const u8, new: [*]const u8) usize {
     if (@hasDecl(@This(), "SYS_rename")) {
         return syscall2(SYS_rename, @ptrToInt(old), @ptrToInt(new));
     } else if (@hasDecl(@This(), "SYS_renameat")) {
-        return syscall4(SYS_renameat, @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(old), @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(new));
+        return syscall4(SYS_renameat, @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(old), @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(new));
     } else {
-        return syscall5(SYS_renameat2, @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(old), @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(new), 0);
+        return syscall5(SYS_renameat2, @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(old), @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(new), 0);
     }
 }
 
@@ -385,17 +385,17 @@ pub fn renameat(oldfd: i32, oldpath: [*]const u8, newfd: i32, newpath: [*]const
     if (@hasDecl(@This(), "SYS_renameat")) {
         return syscall4(
             SYS_renameat,
-            @bitCast(usize, isize(oldfd)),
+            @bitCast(usize, @as(isize, oldfd)),
             @ptrToInt(old),
-            @bitCast(usize, isize(newfd)),
+            @bitCast(usize, @as(isize, newfd)),
             @ptrToInt(new),
         );
     } else {
         return syscall5(
             SYS_renameat2,
-            @bitCast(usize, isize(oldfd)),
+            @bitCast(usize, @as(isize, oldfd)),
             @ptrToInt(old),
-            @bitCast(usize, isize(newfd)),
+            @bitCast(usize, @as(isize, newfd)),
             @ptrToInt(new),
             0,
         );
@@ -406,9 +406,9 @@ pub fn renameat(oldfd: i32, oldpath: [*]const u8, newfd: i32, newpath: [*]const
 pub fn renameat2(oldfd: i32, oldpath: [*]const u8, newfd: i32, newpath: [*]const u8, flags: u32) usize {
     return syscall5(
         SYS_renameat2,
-        @bitCast(usize, isize(oldfd)),
+        @bitCast(usize, @as(isize, oldfd)),
         @ptrToInt(oldpath),
-        @bitCast(usize, isize(newfd)),
+        @bitCast(usize, @as(isize, newfd)),
         @ptrToInt(newpath),
         flags,
     );
@@ -421,7 +421,7 @@ pub fn open(path: [*]const u8, flags: u32, perm: usize) usize {
     } else {
         return syscall4(
             SYS_openat,
-            @bitCast(usize, isize(AT_FDCWD)),
+            @bitCast(usize, @as(isize, AT_FDCWD)),
             @ptrToInt(path),
             flags,
             perm,
@@ -437,7 +437,7 @@ pub fn create(path: [*]const u8, perm: usize) usize {
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn openat(dirfd: i32, path: [*]const u8, flags: u32, mode: usize) usize {
     // dirfd could be negative, for example AT_FDCWD is -100
-    return syscall4(SYS_openat, @bitCast(usize, isize(dirfd)), @ptrToInt(path), flags, mode);
+    return syscall4(SYS_openat, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), flags, mode);
 }
 
 /// See also `clone` (from the arch-specific include)
@@ -451,14 +451,14 @@ pub fn clone2(flags: u32, child_stack_ptr: usize) usize {
 }
 
 pub fn close(fd: i32) usize {
-    return syscall1(SYS_close, @bitCast(usize, isize(fd)));
+    return syscall1(SYS_close, @bitCast(usize, @as(isize, fd)));
 }
 
 /// Can only be called on 32 bit systems. For 64 bit see `lseek`.
 pub fn llseek(fd: i32, offset: u64, result: ?*u64, whence: usize) usize {
     return syscall5(
         SYS__llseek,
-        @bitCast(usize, isize(fd)),
+        @bitCast(usize, @as(isize, fd)),
         @truncate(usize, offset >> 32),
         @truncate(usize, offset),
         @ptrToInt(result),
@@ -468,16 +468,16 @@ pub fn llseek(fd: i32, offset: u64, result: ?*u64, whence: usize) usize {
 
 /// Can only be called on 64 bit systems. For 32 bit see `llseek`.
 pub fn lseek(fd: i32, offset: i64, whence: usize) usize {
-    return syscall3(SYS_lseek, @bitCast(usize, isize(fd)), @bitCast(usize, offset), whence);
+    return syscall3(SYS_lseek, @bitCast(usize, @as(isize, fd)), @bitCast(usize, offset), whence);
 }
 
 pub fn exit(status: i32) noreturn {
-    _ = syscall1(SYS_exit, @bitCast(usize, isize(status)));
+    _ = syscall1(SYS_exit, @bitCast(usize, @as(isize, status)));
     unreachable;
 }
 
 pub fn exit_group(status: i32) noreturn {
-    _ = syscall1(SYS_exit_group, @bitCast(usize, isize(status)));
+    _ = syscall1(SYS_exit_group, @bitCast(usize, @as(isize, status)));
     unreachable;
 }
 
@@ -486,7 +486,7 @@ pub fn getrandom(buf: [*]u8, count: usize, flags: u32) usize {
 }
 
 pub fn kill(pid: i32, sig: i32) usize {
-    return syscall2(SYS_kill, @bitCast(usize, isize(pid)), @bitCast(usize, isize(sig)));
+    return syscall2(SYS_kill, @bitCast(usize, @as(isize, pid)), @bitCast(usize, @as(isize, sig)));
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -494,17 +494,17 @@ pub fn unlink(path: [*]const u8) usize {
     if (@hasDecl(@This(), "SYS_unlink")) {
         return syscall1(SYS_unlink, @ptrToInt(path));
     } else {
-        return syscall3(SYS_unlinkat, @bitCast(usize, isize(AT_FDCWD)), @ptrToInt(path), 0);
+        return syscall3(SYS_unlinkat, @bitCast(usize, @as(isize, AT_FDCWD)), @ptrToInt(path), 0);
     }
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn unlinkat(dirfd: i32, path: [*]const u8, flags: u32) usize {
-    return syscall3(SYS_unlinkat, @bitCast(usize, isize(dirfd)), @ptrToInt(path), flags);
+    return syscall3(SYS_unlinkat, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), flags);
 }
 
 pub fn waitpid(pid: i32, status: *u32, flags: u32) usize {
-    return syscall4(SYS_wait4, @bitCast(usize, isize(pid)), @ptrToInt(status), flags, 0);
+    return syscall4(SYS_wait4, @bitCast(usize, @as(isize, pid)), @ptrToInt(status), flags, 0);
 }
 
 var vdso_clock_gettime = @ptrCast(?*const c_void, init_vdso_clock_gettime);
@@ -519,12 +519,12 @@ pub fn clock_gettime(clk_id: i32, tp: *timespec) usize {
             const f = @ptrCast(vdso_clock_gettime_ty, fn_ptr);
             const rc = f(clk_id, tp);
             switch (rc) {
-                0, @bitCast(usize, isize(-EINVAL)) => return rc,
+                0, @bitCast(usize, @as(isize, -EINVAL)) => return rc,
                 else => {},
             }
         }
     }
-    return syscall2(SYS_clock_gettime, @bitCast(usize, isize(clk_id)), @ptrToInt(tp));
+    return syscall2(SYS_clock_gettime, @bitCast(usize, @as(isize, clk_id)), @ptrToInt(tp));
 }
 
 extern fn init_vdso_clock_gettime(clk: i32, ts: *timespec) usize {
@@ -537,15 +537,15 @@ extern fn init_vdso_clock_gettime(clk: i32, ts: *timespec) usize {
         const f = @ptrCast(vdso_clock_gettime_ty, fn_ptr);
         return f(clk, ts);
     }
-    return @bitCast(usize, isize(-ENOSYS));
+    return @bitCast(usize, @as(isize, -ENOSYS));
 }
 
 pub fn clock_getres(clk_id: i32, tp: *timespec) usize {
-    return syscall2(SYS_clock_getres, @bitCast(usize, isize(clk_id)), @ptrToInt(tp));
+    return syscall2(SYS_clock_getres, @bitCast(usize, @as(isize, clk_id)), @ptrToInt(tp));
 }
 
 pub fn clock_settime(clk_id: i32, tp: *const timespec) usize {
-    return syscall2(SYS_clock_settime, @bitCast(usize, isize(clk_id)), @ptrToInt(tp));
+    return syscall2(SYS_clock_settime, @bitCast(usize, @as(isize, clk_id)), @ptrToInt(tp));
 }
 
 pub fn gettimeofday(tv: *timeval, tz: *timezone) usize {
@@ -594,33 +594,33 @@ pub fn setregid(rgid: u32, egid: u32) usize {
 
 pub fn getuid() u32 {
     if (@hasDecl(@This(), "SYS_getuid32")) {
-        return u32(syscall0(SYS_getuid32));
+        return @as(u32, syscall0(SYS_getuid32));
     } else {
-        return u32(syscall0(SYS_getuid));
+        return @as(u32, syscall0(SYS_getuid));
     }
 }
 
 pub fn getgid() u32 {
     if (@hasDecl(@This(), "SYS_getgid32")) {
-        return u32(syscall0(SYS_getgid32));
+        return @as(u32, syscall0(SYS_getgid32));
     } else {
-        return u32(syscall0(SYS_getgid));
+        return @as(u32, syscall0(SYS_getgid));
     }
 }
 
 pub fn geteuid() u32 {
     if (@hasDecl(@This(), "SYS_geteuid32")) {
-        return u32(syscall0(SYS_geteuid32));
+        return @as(u32, syscall0(SYS_geteuid32));
     } else {
-        return u32(syscall0(SYS_geteuid));
+        return @as(u32, syscall0(SYS_geteuid));
     }
 }
 
 pub fn getegid() u32 {
     if (@hasDecl(@This(), "SYS_getegid32")) {
-        return u32(syscall0(SYS_getegid32));
+        return @as(u32, syscall0(SYS_getegid32));
     } else {
-        return u32(syscall0(SYS_getegid));
+        return @as(u32, syscall0(SYS_getegid));
     }
 }
 
@@ -743,11 +743,11 @@ pub fn sigismember(set: *const sigset_t, sig: u6) bool {
 }
 
 pub fn getsockname(fd: i32, noalias addr: *sockaddr, noalias len: *socklen_t) usize {
-    return syscall3(SYS_getsockname, @bitCast(usize, isize(fd)), @ptrToInt(addr), @ptrToInt(len));
+    return syscall3(SYS_getsockname, @bitCast(usize, @as(isize, fd)), @ptrToInt(addr), @ptrToInt(len));
 }
 
 pub fn getpeername(fd: i32, noalias addr: *sockaddr, noalias len: *socklen_t) usize {
-    return syscall3(SYS_getpeername, @bitCast(usize, isize(fd)), @ptrToInt(addr), @ptrToInt(len));
+    return syscall3(SYS_getpeername, @bitCast(usize, @as(isize, fd)), @ptrToInt(addr), @ptrToInt(len));
 }
 
 pub fn socket(domain: u32, socket_type: u32, protocol: u32) usize {
@@ -755,15 +755,15 @@ pub fn socket(domain: u32, socket_type: u32, protocol: u32) usize {
 }
 
 pub fn setsockopt(fd: i32, level: u32, optname: u32, optval: [*]const u8, optlen: socklen_t) usize {
-    return syscall5(SYS_setsockopt, @bitCast(usize, isize(fd)), level, optname, @ptrToInt(optval), @intCast(usize, optlen));
+    return syscall5(SYS_setsockopt, @bitCast(usize, @as(isize, fd)), level, optname, @ptrToInt(optval), @intCast(usize, optlen));
 }
 
 pub fn getsockopt(fd: i32, level: u32, optname: u32, noalias optval: [*]u8, noalias optlen: *socklen_t) usize {
-    return syscall5(SYS_getsockopt, @bitCast(usize, isize(fd)), level, optname, @ptrToInt(optval), @ptrToInt(optlen));
+    return syscall5(SYS_getsockopt, @bitCast(usize, @as(isize, fd)), level, optname, @ptrToInt(optval), @ptrToInt(optlen));
 }
 
 pub fn sendmsg(fd: i32, msg: *msghdr_const, flags: u32) usize {
-    return syscall3(SYS_sendmsg, @bitCast(usize, isize(fd)), @ptrToInt(msg), flags);
+    return syscall3(SYS_sendmsg, @bitCast(usize, @as(isize, fd)), @ptrToInt(msg), flags);
 }
 
 pub fn sendmmsg(fd: i32, msgvec: [*]mmsghdr_const, vlen: u32, flags: u32) usize {
@@ -781,7 +781,7 @@ pub fn sendmmsg(fd: i32, msgvec: [*]mmsghdr_const, vlen: u32, flags: u32) usize
                     // batch-send all messages up to the current message
                     if (next_unsent < i) {
                         const batch_size = i - next_unsent;
-                        const r = syscall4(SYS_sendmmsg, @bitCast(usize, isize(fd)), @ptrToInt(&msgvec[next_unsent]), batch_size, flags);
+                        const r = syscall4(SYS_sendmmsg, @bitCast(usize, @as(isize, fd)), @ptrToInt(&msgvec[next_unsent]), batch_size, flags);
                         if (getErrno(r) != 0) return next_unsent;
                         if (r < batch_size) return next_unsent + r;
                     }
@@ -797,41 +797,41 @@ pub fn sendmmsg(fd: i32, msgvec: [*]mmsghdr_const, vlen: u32, flags: u32) usize
         }
         if (next_unsent < kvlen or next_unsent == 0) { // want to make sure at least one syscall occurs (e.g. to trigger MSG_EOR)
             const batch_size = kvlen - next_unsent;
-            const r = syscall4(SYS_sendmmsg, @bitCast(usize, isize(fd)), @ptrToInt(&msgvec[next_unsent]), batch_size, flags);
+            const r = syscall4(SYS_sendmmsg, @bitCast(usize, @as(isize, fd)), @ptrToInt(&msgvec[next_unsent]), batch_size, flags);
             if (getErrno(r) != 0) return r;
             return next_unsent + r;
         }
         return kvlen;
     }
-    return syscall4(SYS_sendmmsg, @bitCast(usize, isize(fd)), @ptrToInt(msgvec), vlen, flags);
+    return syscall4(SYS_sendmmsg, @bitCast(usize, @as(isize, fd)), @ptrToInt(msgvec), vlen, flags);
 }
 
 pub fn connect(fd: i32, addr: *const c_void, len: socklen_t) usize {
-    return syscall3(SYS_connect, @bitCast(usize, isize(fd)), @ptrToInt(addr), len);
+    return syscall3(SYS_connect, @bitCast(usize, @as(isize, fd)), @ptrToInt(addr), len);
 }
 
 pub fn recvmsg(fd: i32, msg: *msghdr, flags: u32) usize {
-    return syscall3(SYS_recvmsg, @bitCast(usize, isize(fd)), @ptrToInt(msg), flags);
+    return syscall3(SYS_recvmsg, @bitCast(usize, @as(isize, fd)), @ptrToInt(msg), flags);
 }
 
 pub fn recvfrom(fd: i32, noalias buf: [*]u8, len: usize, flags: u32, noalias addr: ?*sockaddr, noalias alen: ?*socklen_t) usize {
-    return syscall6(SYS_recvfrom, @bitCast(usize, isize(fd)), @ptrToInt(buf), len, flags, @ptrToInt(addr), @ptrToInt(alen));
+    return syscall6(SYS_recvfrom, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), len, flags, @ptrToInt(addr), @ptrToInt(alen));
 }
 
 pub fn shutdown(fd: i32, how: i32) usize {
-    return syscall2(SYS_shutdown, @bitCast(usize, isize(fd)), @bitCast(usize, isize(how)));
+    return syscall2(SYS_shutdown, @bitCast(usize, @as(isize, fd)), @bitCast(usize, @as(isize, how)));
 }
 
 pub fn bind(fd: i32, addr: *const sockaddr, len: socklen_t) usize {
-    return syscall3(SYS_bind, @bitCast(usize, isize(fd)), @ptrToInt(addr), @intCast(usize, len));
+    return syscall3(SYS_bind, @bitCast(usize, @as(isize, fd)), @ptrToInt(addr), @intCast(usize, len));
 }
 
 pub fn listen(fd: i32, backlog: u32) usize {
-    return syscall2(SYS_listen, @bitCast(usize, isize(fd)), backlog);
+    return syscall2(SYS_listen, @bitCast(usize, @as(isize, fd)), backlog);
 }
 
 pub fn sendto(fd: i32, buf: [*]const u8, len: usize, flags: u32, addr: ?*const sockaddr, alen: socklen_t) usize {
-    return syscall6(SYS_sendto, @bitCast(usize, isize(fd)), @ptrToInt(buf), len, flags, @ptrToInt(addr), @intCast(usize, alen));
+    return syscall6(SYS_sendto, @bitCast(usize, @as(isize, fd)), @ptrToInt(buf), len, flags, @ptrToInt(addr), @intCast(usize, alen));
 }
 
 pub fn socketpair(domain: i32, socket_type: i32, protocol: i32, fd: [2]i32) usize {
@@ -843,14 +843,14 @@ pub fn accept(fd: i32, noalias addr: *sockaddr, noalias len: *socklen_t) usize {
 }
 
 pub fn accept4(fd: i32, noalias addr: *sockaddr, noalias len: *socklen_t, flags: u32) usize {
-    return syscall4(SYS_accept4, @bitCast(usize, isize(fd)), @ptrToInt(addr), @ptrToInt(len), flags);
+    return syscall4(SYS_accept4, @bitCast(usize, @as(isize, fd)), @ptrToInt(addr), @ptrToInt(len), flags);
 }
 
 pub fn fstat(fd: i32, stat_buf: *Stat) usize {
     if (@hasDecl(@This(), "SYS_fstat64")) {
-        return syscall2(SYS_fstat64, @bitCast(usize, isize(fd)), @ptrToInt(stat_buf));
+        return syscall2(SYS_fstat64, @bitCast(usize, @as(isize, fd)), @ptrToInt(stat_buf));
     } else {
-        return syscall2(SYS_fstat, @bitCast(usize, isize(fd)), @ptrToInt(stat_buf));
+        return syscall2(SYS_fstat, @bitCast(usize, @as(isize, fd)), @ptrToInt(stat_buf));
     }
 }
 
@@ -875,9 +875,9 @@ pub fn lstat(pathname: [*]const u8, statbuf: *Stat) usize {
 // TODO https://github.com/ziglang/zig/issues/265
 pub fn fstatat(dirfd: i32, path: [*]const u8, stat_buf: *Stat, flags: u32) usize {
     if (@hasDecl(@This(), "SYS_fstatat64")) {
-        return syscall4(SYS_fstatat64, @bitCast(usize, isize(dirfd)), @ptrToInt(path), @ptrToInt(stat_buf), flags);
+        return syscall4(SYS_fstatat64, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), @ptrToInt(stat_buf), flags);
     } else {
-        return syscall4(SYS_fstatat, @bitCast(usize, isize(dirfd)), @ptrToInt(path), @ptrToInt(stat_buf), flags);
+        return syscall4(SYS_fstatat, @bitCast(usize, @as(isize, dirfd)), @ptrToInt(path), @ptrToInt(stat_buf), flags);
     }
 }
 
@@ -885,14 +885,14 @@ pub fn statx(dirfd: i32, path: [*]const u8, flags: u32, mask: u32, statx_buf: *S
     if (@hasDecl(@This(), "SYS_statx")) {
         return syscall5(
             SYS_statx,
-            @bitCast(usize, isize(dirfd)),
+            @bitCast(usize, @as(isize, dirfd)),
             @ptrToInt(path),
             flags,
             mask,
             @ptrToInt(statx_buf),
         );
     }
-    return @bitCast(usize, isize(-ENOSYS));
+    return @bitCast(usize, @as(isize, -ENOSYS));
 }
 
 // TODO https://github.com/ziglang/zig/issues/265
@@ -959,7 +959,7 @@ pub fn sched_yield() usize {
 }
 
 pub fn sched_getaffinity(pid: i32, size: usize, set: *cpu_set_t) usize {
-    const rc = syscall3(SYS_sched_getaffinity, @bitCast(usize, isize(pid)), size, @ptrToInt(set));
+    const rc = syscall3(SYS_sched_getaffinity, @bitCast(usize, @as(isize, pid)), size, @ptrToInt(set));
     if (@bitCast(isize, rc) < 0) return rc;
     if (rc < size) @memset(@ptrCast([*]u8, set) + rc, 0, size - rc);
     return 0;
@@ -974,7 +974,7 @@ pub fn epoll_create1(flags: usize) usize {
 }
 
 pub fn epoll_ctl(epoll_fd: i32, op: u32, fd: i32, ev: ?*epoll_event) usize {
-    return syscall4(SYS_epoll_ctl, @bitCast(usize, isize(epoll_fd)), @intCast(usize, op), @bitCast(usize, isize(fd)), @ptrToInt(ev));
+    return syscall4(SYS_epoll_ctl, @bitCast(usize, @as(isize, epoll_fd)), @intCast(usize, op), @bitCast(usize, @as(isize, fd)), @ptrToInt(ev));
 }
 
 pub fn epoll_wait(epoll_fd: i32, events: [*]epoll_event, maxevents: u32, timeout: i32) usize {
@@ -984,10 +984,10 @@ pub fn epoll_wait(epoll_fd: i32, events: [*]epoll_event, maxevents: u32, timeout
 pub fn epoll_pwait(epoll_fd: i32, events: [*]epoll_event, maxevents: u32, timeout: i32, sigmask: ?*sigset_t) usize {
     return syscall6(
         SYS_epoll_pwait,
-        @bitCast(usize, isize(epoll_fd)),
+        @bitCast(usize, @as(isize, epoll_fd)),
         @ptrToInt(events),
         @intCast(usize, maxevents),
-        @bitCast(usize, isize(timeout)),
+        @bitCast(usize, @as(isize, timeout)),
         @ptrToInt(sigmask),
         @sizeOf(sigset_t),
     );
@@ -998,7 +998,7 @@ pub fn eventfd(count: u32, flags: u32) usize {
 }
 
 pub fn timerfd_create(clockid: i32, flags: u32) usize {
-    return syscall2(SYS_timerfd_create, @bitCast(usize, isize(clockid)), flags);
+    return syscall2(SYS_timerfd_create, @bitCast(usize, @as(isize, clockid)), flags);
 }
 
 pub const itimerspec = extern struct {
@@ -1007,11 +1007,11 @@ pub const itimerspec = extern struct {
 };
 
 pub fn timerfd_gettime(fd: i32, curr_value: *itimerspec) usize {
-    return syscall2(SYS_timerfd_gettime, @bitCast(usize, isize(fd)), @ptrToInt(curr_value));
+    return syscall2(SYS_timerfd_gettime, @bitCast(usize, @as(isize, fd)), @ptrToInt(curr_value));
 }
 
 pub fn timerfd_settime(fd: i32, flags: u32, new_value: *const itimerspec, old_value: ?*itimerspec) usize {
-    return syscall4(SYS_timerfd_settime, @bitCast(usize, isize(fd)), flags, @ptrToInt(new_value), @ptrToInt(old_value));
+    return syscall4(SYS_timerfd_settime, @bitCast(usize, @as(isize, fd)), flags, @ptrToInt(new_value), @ptrToInt(old_value));
 }
 
 pub fn unshare(flags: usize) usize {
@@ -1096,11 +1096,11 @@ pub fn io_uring_setup(entries: u32, p: *io_uring_params) usize {
 }
 
 pub fn io_uring_enter(fd: i32, to_submit: u32, min_complete: u32, flags: u32, sig: ?*sigset_t) usize {
-    return syscall6(SYS_io_uring_enter, @bitCast(usize, isize(fd)), to_submit, min_complete, flags, @ptrToInt(sig), NSIG / 8);
+    return syscall6(SYS_io_uring_enter, @bitCast(usize, @as(isize, fd)), to_submit, min_complete, flags, @ptrToInt(sig), NSIG / 8);
 }
 
 pub fn io_uring_register(fd: i32, opcode: u32, arg: ?*const c_void, nr_args: u32) usize {
-    return syscall4(SYS_io_uring_register, @bitCast(usize, isize(fd)), opcode, @ptrToInt(arg), nr_args);
+    return syscall4(SYS_io_uring_register, @bitCast(usize, @as(isize, fd)), opcode, @ptrToInt(arg), nr_args);
 }
 
 test "" {