Reduce use of deprecated IO types

Related: #4917

25 files changed, 79 insertions, 79 deletions

diff --git a/lib/std/Progress.zig b/lib/std/Progress.zig
index 6226e34248..ca9fb8ea1f 100644
--- a/lib/std/Progress.zig
+++ b/lib/std/Progress.zig
@@ -271,7 +271,7 @@ fn refreshWithHeldLock(self: *Progress) void {
 pub fn log(self: *Progress, comptime format: []const u8, args: anytype) void {
     const file = self.terminal orelse return;
     self.refresh();
-    file.outStream().print(format, args) catch {
+    file.writer().print(format, args) catch {
         self.terminal = null;
         return;
     };
diff --git a/lib/std/atomic/queue.zig b/lib/std/atomic/queue.zig
index 19d04d041a..fa3711cd9f 100644
--- a/lib/std/atomic/queue.zig
+++ b/lib/std/atomic/queue.zig
@@ -122,7 +122,7 @@ pub fn Queue(comptime T: type) type {
 
         /// Dumps the contents of the queue to `stderr`.
         pub fn dump(self: *Self) void {
-            self.dumpToStream(std.io.getStdErr().outStream()) catch return;
+            self.dumpToStream(std.io.getStdErr().writer()) catch return;
         }
 
         /// Dumps the contents of the queue to `stream`.
@@ -351,7 +351,7 @@ test "std.atomic.Queue dump" {
 
     // Test empty stream
     fbs.reset();
-    try queue.dumpToStream(fbs.outStream());
+    try queue.dumpToStream(fbs.writer());
     expect(mem.eql(u8, buffer[0..fbs.pos],
         \\head: (null)
         \\tail: (null)
@@ -367,7 +367,7 @@ test "std.atomic.Queue dump" {
     queue.put(&node_0);
 
     fbs.reset();
-    try queue.dumpToStream(fbs.outStream());
+    try queue.dumpToStream(fbs.writer());
 
     var expected = try std.fmt.bufPrint(expected_buffer[0..],
         \\head: 0x{x}=1
@@ -387,7 +387,7 @@ test "std.atomic.Queue dump" {
     queue.put(&node_1);
 
     fbs.reset();
-    try queue.dumpToStream(fbs.outStream());
+    try queue.dumpToStream(fbs.writer());
 
     expected = try std.fmt.bufPrint(expected_buffer[0..],
         \\head: 0x{x}=1
diff --git a/lib/std/build.zig b/lib/std/build.zig
index 0d17b4753a..cb4cb229e3 100644
--- a/lib/std/build.zig
+++ b/lib/std/build.zig
@@ -1042,7 +1042,7 @@ pub const Builder = struct {
 
         try child.spawn();
 
-        const stdout = try child.stdout.?.inStream().readAllAlloc(self.allocator, max_output_size);
+        const stdout = try child.stdout.?.reader().readAllAlloc(self.allocator, max_output_size);
         errdefer self.allocator.free(stdout);
 
         const term = try child.wait();
@@ -1849,7 +1849,7 @@ pub const LibExeObjStep = struct {
     }
 
     pub fn addBuildOption(self: *LibExeObjStep, comptime T: type, name: []const u8, value: T) void {
-        const out = self.build_options_contents.outStream();
+        const out = self.build_options_contents.writer();
         switch (T) {
             []const []const u8 => {
                 out.print("pub const {z}: []const []const u8 = &[_][]const u8{{\n", .{name}) catch unreachable;
@@ -2295,16 +2295,16 @@ pub const LibExeObjStep = struct {
             } else {
                 var mcpu_buffer = std.ArrayList(u8).init(builder.allocator);
 
-                try mcpu_buffer.outStream().print("-mcpu={s}", .{cross.cpu.model.name});
+                try mcpu_buffer.writer().print("-mcpu={s}", .{cross.cpu.model.name});
 
                 for (all_features) |feature, i_usize| {
                     const i = @intCast(std.Target.Cpu.Feature.Set.Index, i_usize);
                     const in_cpu_set = populated_cpu_features.isEnabled(i);
                     const in_actual_set = cross.cpu.features.isEnabled(i);
                     if (in_cpu_set and !in_actual_set) {
-                        try mcpu_buffer.outStream().print("-{s}", .{feature.name});
+                        try mcpu_buffer.writer().print("-{s}", .{feature.name});
                     } else if (!in_cpu_set and in_actual_set) {
-                        try mcpu_buffer.outStream().print("+{s}", .{feature.name});
+                        try mcpu_buffer.writer().print("+{s}", .{feature.name});
                     }
                 }
 
diff --git a/lib/std/build/run.zig b/lib/std/build/run.zig
index 36a4a1a843..8f8fa2eba0 100644
--- a/lib/std/build/run.zig
+++ b/lib/std/build/run.zig
@@ -200,7 +200,7 @@ pub const RunStep = struct {
 
         switch (self.stdout_action) {
             .expect_exact, .expect_matches => {
-                stdout = child.stdout.?.inStream().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
+                stdout = child.stdout.?.reader().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
             },
             .inherit, .ignore => {},
         }
@@ -210,7 +210,7 @@ pub const RunStep = struct {
 
         switch (self.stderr_action) {
             .expect_exact, .expect_matches => {
-                stderr = child.stderr.?.inStream().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
+                stderr = child.stderr.?.reader().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
             },
             .inherit, .ignore => {},
         }
diff --git a/lib/std/child_process.zig b/lib/std/child_process.zig
index 4360cc7d73..d37dd9fdf5 100644
--- a/lib/std/child_process.zig
+++ b/lib/std/child_process.zig
@@ -922,7 +922,7 @@ fn writeIntFd(fd: i32, value: ErrInt) !void {
         .capable_io_mode = .blocking,
         .intended_io_mode = .blocking,
     };
-    file.outStream().writeIntNative(u64, @intCast(u64, value)) catch return error.SystemResources;
+    file.writer().writeIntNative(u64, @intCast(u64, value)) catch return error.SystemResources;
 }
 
 fn readIntFd(fd: i32) !ErrInt {
diff --git a/lib/std/coff.zig b/lib/std/coff.zig
index fdc2ec5a82..85000bf8cb 100644
--- a/lib/std/coff.zig
+++ b/lib/std/coff.zig
@@ -127,7 +127,7 @@ pub const Coff = struct {
     pub fn loadHeader(self: *Coff) !void {
         const pe_pointer_offset = 0x3C;
 
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
 
         var magic: [2]u8 = undefined;
         try in.readNoEof(magic[0..]);
@@ -163,7 +163,7 @@ pub const Coff = struct {
     }
 
     fn loadOptionalHeader(self: *Coff) !void {
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
         self.pe_header.magic = try in.readIntLittle(u16);
         // For now we're only interested in finding the reference to the .pdb,
         // so we'll skip most of this header, which size is different in 32
@@ -206,7 +206,7 @@ pub const Coff = struct {
         const debug_dir = &self.pe_header.data_directory[DEBUG_DIRECTORY];
         const file_offset = debug_dir.virtual_address - header.virtual_address + header.pointer_to_raw_data;
 
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
         try self.in_file.seekTo(file_offset);
 
         // Find the correct DebugDirectoryEntry, and where its data is stored.
@@ -257,7 +257,7 @@ pub const Coff = struct {
 
         try self.sections.ensureCapacity(self.coff_header.number_of_sections);
 
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
 
         var name: [8]u8 = undefined;
 
diff --git a/lib/std/crypto/benchmark.zig b/lib/std/crypto/benchmark.zig
index 5b3b837d13..00336aef87 100644
--- a/lib/std/crypto/benchmark.zig
+++ b/lib/std/crypto/benchmark.zig
@@ -314,7 +314,7 @@ fn mode(comptime x: comptime_int) comptime_int {
 }
 
 pub fn main() !void {
-    const stdout = std.io.getStdOut().outStream();
+    const stdout = std.io.getStdOut().writer();
 
     var buffer: [1024]u8 = undefined;
     var fixed = std.heap.FixedBufferAllocator.init(buffer[0..]);
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index 073f68da5d..b19f96892f 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -517,15 +517,15 @@ fn populateModule(di: *ModuleDebugInfo, mod: *Module) !void {
 
     const modi = di.pdb.getStreamById(mod.mod_info.ModuleSymStream) orelse return error.MissingDebugInfo;
 
-    const signature = try modi.inStream().readIntLittle(u32);
+    const signature = try modi.reader().readIntLittle(u32);
     if (signature != 4)
         return error.InvalidDebugInfo;
 
     mod.symbols = try allocator.alloc(u8, mod.mod_info.SymByteSize - 4);
-    try modi.inStream().readNoEof(mod.symbols);
+    try modi.reader().readNoEof(mod.symbols);
 
     mod.subsect_info = try allocator.alloc(u8, mod.mod_info.C13ByteSize);
-    try modi.inStream().readNoEof(mod.subsect_info);
+    try modi.reader().readNoEof(mod.subsect_info);
 
     var sect_offset: usize = 0;
     var skip_len: usize = undefined;
@@ -704,11 +704,11 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         try di.pdb.openFile(di.coff, path);
 
         var pdb_stream = di.pdb.getStream(pdb.StreamType.Pdb) orelse return error.InvalidDebugInfo;
-        const version = try pdb_stream.inStream().readIntLittle(u32);
-        const signature = try pdb_stream.inStream().readIntLittle(u32);
-        const age = try pdb_stream.inStream().readIntLittle(u32);
+        const version = try pdb_stream.reader().readIntLittle(u32);
+        const signature = try pdb_stream.reader().readIntLittle(u32);
+        const age = try pdb_stream.reader().readIntLittle(u32);
         var guid: [16]u8 = undefined;
-        try pdb_stream.inStream().readNoEof(&guid);
+        try pdb_stream.reader().readNoEof(&guid);
         if (version != 20000404) // VC70, only value observed by LLVM team
             return error.UnknownPDBVersion;
         if (!mem.eql(u8, &di.coff.guid, &guid) or di.coff.age != age)
@@ -716,9 +716,9 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         // We validated the executable and pdb match.
 
         const string_table_index = str_tab_index: {
-            const name_bytes_len = try pdb_stream.inStream().readIntLittle(u32);
+            const name_bytes_len = try pdb_stream.reader().readIntLittle(u32);
             const name_bytes = try allocator.alloc(u8, name_bytes_len);
-            try pdb_stream.inStream().readNoEof(name_bytes);
+            try pdb_stream.reader().readNoEof(name_bytes);
 
             const HashTableHeader = packed struct {
                 Size: u32,
@@ -728,17 +728,17 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
                     return cap * 2 / 3 + 1;
                 }
             };
-            const hash_tbl_hdr = try pdb_stream.inStream().readStruct(HashTableHeader);
+            const hash_tbl_hdr = try pdb_stream.reader().readStruct(HashTableHeader);
             if (hash_tbl_hdr.Capacity == 0)
                 return error.InvalidDebugInfo;
 
             if (hash_tbl_hdr.Size > HashTableHeader.maxLoad(hash_tbl_hdr.Capacity))
                 return error.InvalidDebugInfo;
 
-            const present = try readSparseBitVector(&pdb_stream.inStream(), allocator);
+            const present = try readSparseBitVector(&pdb_stream.reader(), allocator);
             if (present.len != hash_tbl_hdr.Size)
                 return error.InvalidDebugInfo;
-            const deleted = try readSparseBitVector(&pdb_stream.inStream(), allocator);
+            const deleted = try readSparseBitVector(&pdb_stream.reader(), allocator);
 
             const Bucket = struct {
                 first: u32,
@@ -746,8 +746,8 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
             };
             const bucket_list = try allocator.alloc(Bucket, present.len);
             for (present) |_| {
-                const name_offset = try pdb_stream.inStream().readIntLittle(u32);
-                const name_index = try pdb_stream.inStream().readIntLittle(u32);
+                const name_offset = try pdb_stream.reader().readIntLittle(u32);
+                const name_index = try pdb_stream.reader().readIntLittle(u32);
                 const name = mem.spanZ(std.meta.assumeSentinel(name_bytes.ptr + name_offset, 0));
                 if (mem.eql(u8, name, "/names")) {
                     break :str_tab_index name_index;
@@ -762,7 +762,7 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         const dbi = di.pdb.dbi;
 
         // Dbi Header
-        const dbi_stream_header = try dbi.inStream().readStruct(pdb.DbiStreamHeader);
+        const dbi_stream_header = try dbi.reader().readStruct(pdb.DbiStreamHeader);
         if (dbi_stream_header.VersionHeader != 19990903) // V70, only value observed by LLVM team
             return error.UnknownPDBVersion;
         if (dbi_stream_header.Age != age)
@@ -776,7 +776,7 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         // Module Info Substream
         var mod_info_offset: usize = 0;
         while (mod_info_offset != mod_info_size) {
-            const mod_info = try dbi.inStream().readStruct(pdb.ModInfo);
+            const mod_info = try dbi.reader().readStruct(pdb.ModInfo);
             var this_record_len: usize = @sizeOf(pdb.ModInfo);
 
             const module_name = try dbi.readNullTermString(allocator);
@@ -814,14 +814,14 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         var sect_contribs = ArrayList(pdb.SectionContribEntry).init(allocator);
         var sect_cont_offset: usize = 0;
         if (section_contrib_size != 0) {
-            const ver = @intToEnum(pdb.SectionContrSubstreamVersion, try dbi.inStream().readIntLittle(u32));
+            const ver = @intToEnum(pdb.SectionContrSubstreamVersion, try dbi.reader().readIntLittle(u32));
             if (ver != pdb.SectionContrSubstreamVersion.Ver60)
                 return error.InvalidDebugInfo;
             sect_cont_offset += @sizeOf(u32);
         }
         while (sect_cont_offset != section_contrib_size) {
             const entry = try sect_contribs.addOne();
-            entry.* = try dbi.inStream().readStruct(pdb.SectionContribEntry);
+            entry.* = try dbi.reader().readStruct(pdb.SectionContribEntry);
             sect_cont_offset += @sizeOf(pdb.SectionContribEntry);
 
             if (sect_cont_offset > section_contrib_size)
diff --git a/lib/std/dwarf.zig b/lib/std/dwarf.zig
index 2e732cbc75..6769a139da 100644
--- a/lib/std/dwarf.zig
+++ b/lib/std/dwarf.zig
@@ -408,7 +408,7 @@ pub const DwarfInfo = struct {
 
     fn scanAllFunctions(di: *DwarfInfo) !void {
         var stream = io.fixedBufferStream(di.debug_info);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
         var this_unit_offset: u64 = 0;
 
@@ -512,7 +512,7 @@ pub const DwarfInfo = struct {
 
     fn scanAllCompileUnits(di: *DwarfInfo) !void {
         var stream = io.fixedBufferStream(di.debug_info);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
         var this_unit_offset: u64 = 0;
 
@@ -585,7 +585,7 @@ pub const DwarfInfo = struct {
             if (di.debug_ranges) |debug_ranges| {
                 if (compile_unit.die.getAttrSecOffset(AT_ranges)) |ranges_offset| {
                     var stream = io.fixedBufferStream(debug_ranges);
-                    const in = &stream.inStream();
+                    const in = &stream.reader();
                     const seekable = &stream.seekableStream();
 
                     // All the addresses in the list are relative to the value
@@ -640,7 +640,7 @@ pub const DwarfInfo = struct {
 
     fn parseAbbrevTable(di: *DwarfInfo, offset: u64) !AbbrevTable {
         var stream = io.fixedBufferStream(di.debug_abbrev);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
 
         try seekable.seekTo(offset);
@@ -691,7 +691,7 @@ pub const DwarfInfo = struct {
 
     pub fn getLineNumberInfo(di: *DwarfInfo, compile_unit: CompileUnit, target_address: usize) !debug.LineInfo {
         var stream = io.fixedBufferStream(di.debug_line);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
 
         const compile_unit_cwd = try compile_unit.die.getAttrString(di, AT_comp_dir);
diff --git a/lib/std/heap/logging_allocator.zig b/lib/std/heap/logging_allocator.zig
index 47a584bb1d..7920138e9b 100644
--- a/lib/std/heap/logging_allocator.zig
+++ b/lib/std/heap/logging_allocator.zig
@@ -89,7 +89,7 @@ test "LoggingAllocator" {
 
     var allocator_buf: [10]u8 = undefined;
     var fixedBufferAllocator = std.mem.validationWrap(std.heap.FixedBufferAllocator.init(&allocator_buf));
-    const allocator = &loggingAllocator(&fixedBufferAllocator.allocator, fbs.outStream()).allocator;
+    const allocator = &loggingAllocator(&fixedBufferAllocator.allocator, fbs.writer()).allocator;
 
     var a = try allocator.alloc(u8, 10);
     a = allocator.shrink(a, 5);
diff --git a/lib/std/io/buffered_atomic_file.zig b/lib/std/io/buffered_atomic_file.zig
index 9d65e9d193..66c349d318 100644
--- a/lib/std/io/buffered_atomic_file.zig
+++ b/lib/std/io/buffered_atomic_file.zig
@@ -38,7 +38,7 @@ pub const BufferedAtomicFile = struct {
         self.atomic_file = try dir.atomicFile(dest_path, atomic_file_options);
         errdefer self.atomic_file.deinit();
 
-        self.file_stream = self.atomic_file.file.outStream();
+        self.file_stream = self.atomic_file.file.writer();
         self.buffered_stream = .{ .unbuffered_writer = self.file_stream };
         return self;
     }
diff --git a/lib/std/io/fixed_buffer_stream.zig b/lib/std/io/fixed_buffer_stream.zig
index b36949e538..1711b6da1b 100644
--- a/lib/std/io/fixed_buffer_stream.zig
+++ b/lib/std/io/fixed_buffer_stream.zig
@@ -45,7 +45,7 @@ pub fn FixedBufferStream(comptime Buffer: type) type {
             return .{ .context = self };
         }
 
-        /// Deprecated: use `inStream`
+        /// Deprecated: use `reader`
         pub fn inStream(self: *Self) InStream {
             return .{ .context = self };
         }
diff --git a/lib/std/io/test.zig b/lib/std/io/test.zig
index 85357ae58a..9fdef0de1d 100644
--- a/lib/std/io/test.zig
+++ b/lib/std/io/test.zig
@@ -30,8 +30,8 @@ test "write a file, read it, then delete it" {
         var file = try tmp.dir.createFile(tmp_file_name, .{});
         defer file.close();
 
-        var buf_stream = io.bufferedOutStream(file.outStream());
-        const st = buf_stream.outStream();
+        var buf_stream = io.bufferedWriter(file.writer());
+        const st = buf_stream.writer();
         try st.print("begin", .{});
         try st.writeAll(data[0..]);
         try st.print("end", .{});
@@ -72,7 +72,7 @@ test "BitStreams with File Stream" {
         var file = try tmp.dir.createFile(tmp_file_name, .{});
         defer file.close();
 
-        var bit_stream = io.bitOutStream(builtin.endian, file.outStream());
+        var bit_stream = io.bitWriter(builtin.endian, file.writer());
 
         try bit_stream.writeBits(@as(u2, 1), 1);
         try bit_stream.writeBits(@as(u5, 2), 2);
diff --git a/lib/std/json.zig b/lib/std/json.zig
index 87808a7350..5cbdb4319e 100644
--- a/lib/std/json.zig
+++ b/lib/std/json.zig
@@ -1323,31 +1323,31 @@ test "Value.jsonStringify" {
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try @as(Value, .Null).jsonStringify(.{}, fbs.outStream());
+        try @as(Value, .Null).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "null");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .Bool = true }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Bool = true }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "true");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .Integer = 42 }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Integer = 42 }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "42");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .Float = 42 }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Float = 42 }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "4.2e+01");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .String = "weeee" }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .String = "weeee" }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "\"weeee\"");
     }
     {
@@ -1360,7 +1360,7 @@ test "Value.jsonStringify" {
         };
         try (Value{
             .Array = Array.fromOwnedSlice(undefined, &vals),
-        }).jsonStringify(.{}, fbs.outStream());
+        }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "[1,2,3]");
     }
     {
@@ -1369,7 +1369,7 @@ test "Value.jsonStringify" {
         var obj = ObjectMap.init(testing.allocator);
         defer obj.deinit();
         try obj.putNoClobber("a", .{ .String = "b" });
-        try (Value{ .Object = obj }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Object = obj }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "{\"a\":\"b\"}");
     }
 }
@@ -2223,7 +2223,7 @@ test "write json then parse it" {
     var out_buffer: [1000]u8 = undefined;
 
     var fixed_buffer_stream = std.io.fixedBufferStream(&out_buffer);
-    const out_stream = fixed_buffer_stream.outStream();
+    const out_stream = fixed_buffer_stream.writer();
     var jw = writeStream(out_stream, 4);
 
     try jw.beginObject();
diff --git a/lib/std/json/write_stream.zig b/lib/std/json/write_stream.zig
index 9322ca5429..b4a8aed84c 100644
--- a/lib/std/json/write_stream.zig
+++ b/lib/std/json/write_stream.zig
@@ -238,7 +238,7 @@ pub fn writeStream(
 test "json write stream" {
     var out_buf: [1024]u8 = undefined;
     var slice_stream = std.io.fixedBufferStream(&out_buf);
-    const out = slice_stream.outStream();
+    const out = slice_stream.writer();
 
     var arena_allocator = std.heap.ArenaAllocator.init(std.testing.allocator);
     defer arena_allocator.deinit();
diff --git a/lib/std/net.zig b/lib/std/net.zig
index da35bd88b0..037df76907 100644
--- a/lib/std/net.zig
+++ b/lib/std/net.zig
@@ -1106,7 +1106,7 @@ fn linuxLookupNameFromHosts(
     };
     defer file.close();
 
-    const stream = std.io.bufferedInStream(file.inStream()).inStream();
+    const stream = std.io.bufferedReader(file.reader()).reader();
     var line_buf: [512]u8 = undefined;
     while (stream.readUntilDelimiterOrEof(&line_buf, '\n') catch |err| switch (err) {
         error.StreamTooLong => blk: {
@@ -1304,7 +1304,7 @@ fn getResolvConf(allocator: *mem.Allocator, rc: *ResolvConf) !void {
     };
     defer file.close();
 
-    const stream = std.io.bufferedInStream(file.inStream()).inStream();
+    const stream = std.io.bufferedReader(file.reader()).reader();
     var line_buf: [512]u8 = undefined;
     while (stream.readUntilDelimiterOrEof(&line_buf, '\n') catch |err| switch (err) {
         error.StreamTooLong => blk: {
diff --git a/lib/std/net/test.zig b/lib/std/net/test.zig
index 110c6ec9c0..74ae1ddf4f 100644
--- a/lib/std/net/test.zig
+++ b/lib/std/net/test.zig
@@ -249,6 +249,6 @@ fn testServer(server: *net.StreamServer) anyerror!void {
 
     var client = try server.accept();
 
-    const stream = client.file.outStream();
+    const stream = client.file.writer();
     try stream.print("hello from server\n", .{});
 }
diff --git a/lib/std/os.zig b/lib/std/os.zig
index e9bf6379cc..42bdf486d7 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -191,7 +191,7 @@ fn getRandomBytesDevURandom(buf: []u8) !void {
         .capable_io_mode = .blocking,
         .intended_io_mode = .blocking,
     };
-    const stream = file.inStream();
+    const stream = file.reader();
     stream.readNoEof(buf) catch return error.Unexpected;
 }
 
diff --git a/lib/std/os/test.zig b/lib/std/os/test.zig
index 65dee90e62..0904a8585f 100644
--- a/lib/std/os/test.zig
+++ b/lib/std/os/test.zig
@@ -475,7 +475,7 @@ test "mmap" {
         const file = try tmp.dir.createFile(test_out_file, .{});
         defer file.close();
 
-        const stream = file.outStream();
+        const stream = file.writer();
 
         var i: u32 = 0;
         while (i < alloc_size / @sizeOf(u32)) : (i += 1) {
@@ -499,7 +499,7 @@ test "mmap" {
         defer os.munmap(data);
 
         var mem_stream = io.fixedBufferStream(data);
-        const stream = mem_stream.inStream();
+        const stream = mem_stream.reader();
 
         var i: u32 = 0;
         while (i < alloc_size / @sizeOf(u32)) : (i += 1) {
@@ -523,7 +523,7 @@ test "mmap" {
         defer os.munmap(data);
 
         var mem_stream = io.fixedBufferStream(data);
-        const stream = mem_stream.inStream();
+        const stream = mem_stream.reader();
 
         var i: u32 = alloc_size / 2 / @sizeOf(u32);
         while (i < alloc_size / @sizeOf(u32)) : (i += 1) {
diff --git a/lib/std/special/build_runner.zig b/lib/std/special/build_runner.zig
index f2fa2dc3b8..0b7baf0fc1 100644
--- a/lib/std/special/build_runner.zig
+++ b/lib/std/special/build_runner.zig
@@ -57,8 +57,8 @@ pub fn main() !void {
 
     var targets = ArrayList([]const u8).init(allocator);
 
-    const stderr_stream = io.getStdErr().outStream();
-    const stdout_stream = io.getStdOut().outStream();
+    const stderr_stream = io.getStdErr().writer();
+    const stdout_stream = io.getStdOut().writer();
 
     while (nextArg(args, &arg_idx)) |arg| {
         if (mem.startsWith(u8, arg, "-D")) {
diff --git a/lib/std/unicode/throughput_test.zig b/lib/std/unicode/throughput_test.zig
index 2676a30cb2..8f9f9d9cb7 100644
--- a/lib/std/unicode/throughput_test.zig
+++ b/lib/std/unicode/throughput_test.zig
@@ -45,7 +45,7 @@ fn benchmarkCodepointCount(buf: []const u8) !ResultCount {
 }
 
 pub fn main() !void {
-    const stdout = std.io.getStdOut().outStream();
+    const stdout = std.io.getStdOut().writer();
 
     const args = try std.process.argsAlloc(std.heap.page_allocator);
 
diff --git a/lib/std/zig/cross_target.zig b/lib/std/zig/cross_target.zig
index 060dd83caf..f0849f9a03 100644
--- a/lib/std/zig/cross_target.zig
+++ b/lib/std/zig/cross_target.zig
@@ -519,29 +519,29 @@ pub const CrossTarget = struct {
         var result = std.ArrayList(u8).init(allocator);
         defer result.deinit();
 
-        try result.outStream().print("{s}-{s}", .{ arch_name, os_name });
+        try result.writer().print("{s}-{s}", .{ arch_name, os_name });
 
         // The zig target syntax does not allow specifying a max os version with no min, so
         // if either are present, we need the min.
         if (self.os_version_min != null or self.os_version_max != null) {
             switch (self.getOsVersionMin()) {
                 .none => {},
-                .semver => |v| try result.outStream().print(".{}", .{v}),
-                .windows => |v| try result.outStream().print("{s}", .{v}),
+                .semver => |v| try result.writer().print(".{}", .{v}),
+                .windows => |v| try result.writer().print("{s}", .{v}),
             }
         }
         if (self.os_version_max) |max| {
             switch (max) {
                 .none => {},
-                .semver => |v| try result.outStream().print("...{}", .{v}),
-                .windows => |v| try result.outStream().print("..{s}", .{v}),
+                .semver => |v| try result.writer().print("...{}", .{v}),
+                .windows => |v| try result.writer().print("..{s}", .{v}),
             }
         }
 
         if (self.glibc_version) |v| {
-            try result.outStream().print("-{s}.{}", .{ @tagName(self.getAbi()), v });
+            try result.writer().print("-{s}.{}", .{ @tagName(self.getAbi()), v });
         } else if (self.abi) |abi| {
-            try result.outStream().print("-{s}", .{@tagName(abi)});
+            try result.writer().print("-{s}", .{@tagName(abi)});
         }
 
         return result.toOwnedSlice();
diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index 63d04f9a80..d7cc1208a2 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -3734,7 +3734,7 @@ const maxInt = std.math.maxInt;
 var fixed_buffer_mem: [100 * 1024]u8 = undefined;
 
 fn testParse(source: []const u8, allocator: *mem.Allocator, anything_changed: *bool) ![]u8 {
-    const stderr = io.getStdErr().outStream();
+    const stderr = io.getStdErr().writer();
 
     const tree = try std.zig.parse(allocator, source);
     defer tree.deinit();
@@ -3767,8 +3767,8 @@ fn testParse(source: []const u8, allocator: *mem.Allocator, anything_changed: *b
     var buffer = std.ArrayList(u8).init(allocator);
     errdefer buffer.deinit();
 
-    const outStream = buffer.outStream();
-    anything_changed.* = try std.zig.render(allocator, outStream, tree);
+    const writer = buffer.writer();
+    anything_changed.* = try std.zig.render(allocator, writer, tree);
     return buffer.toOwnedSlice();
 }
 fn testTransform(source: []const u8, expected_source: []const u8) !void {
diff --git a/lib/std/zig/perf_test.zig b/lib/std/zig/perf_test.zig
index e1c58c1469..b111170902 100644
--- a/lib/std/zig/perf_test.zig
+++ b/lib/std/zig/perf_test.zig
@@ -29,7 +29,7 @@ pub fn main() !void {
     const mb_per_sec = bytes_per_sec / (1024 * 1024);
 
     var stdout_file = std.io.getStdOut();
-    const stdout = stdout_file.outStream();
+    const stdout = stdout_file.writer();
     try stdout.print("{:.3} MiB/s, {} KiB used \n", .{ mb_per_sec, memory_used / 1024 });
 }
 
diff --git a/lib/std/zig/render.zig b/lib/std/zig/render.zig
index 6931b19250..b882d71cfd 100644
--- a/lib/std/zig/render.zig
+++ b/lib/std/zig/render.zig
@@ -790,7 +790,7 @@ fn renderExpression(
                         const section_exprs = row_exprs[0..section_end];
 
                         // Null stream for counting the printed length of each expression
-                        var line_find_stream = std.io.findByteOutStream('\n', std.io.null_out_stream);
+                        var line_find_stream = std.io.findByteOutStream('\n', std.io.null_writer);
                         var counting_stream = std.io.countingOutStream(line_find_stream.writer());
                         var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, counting_stream.writer());
 
@@ -954,7 +954,7 @@ fn renderExpression(
             const expr_outputs_one_line = blk: {
                 // render field expressions until a LF is found
                 for (field_inits) |field_init| {
-                    var find_stream = std.io.findByteOutStream('\n', std.io.null_out_stream);
+                    var find_stream = std.io.findByteOutStream('\n', std.io.null_writer);
                     var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, find_stream.writer());
 
                     try renderExpression(allocator, &auto_indenting_stream, tree, field_init, Space.None);