From 28c7fe60b6de6e3c32e082a0abfb5a7bac8fc45a Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Thu, 19 Sep 2019 11:14:42 -0400
Subject: [PATCH] add docs for `@splat`

---
 doc/langref.html.in | 36 ++++++++++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/doc/langref.html.in b/doc/langref.html.in
index 61fc06fd02..1158135dab 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -5864,7 +5864,7 @@ volatile (
     : [number] "{rax}" (number),
         [arg1] "{rdi}" (arg1)
 // Next is the list of clobbers. These declare a set of registers whose
-// values will not be preserved by the execution of this assembly code. 
+// values will not be preserved by the execution of this assembly code.
 // These do not include output or input registers. The special clobber
 // value of "memory" means that the assembly writes to arbitrary undeclared
 // memory locations - not only the memory pointed to by a declared indirect
@@ -5885,7 +5885,7 @@ volatile (
       </p>
       {#header_open|Output Constraints#}
       <p>
-      Output constraints are still considered to be unstable in Zig, and 
+      Output constraints are still considered to be unstable in Zig, and
       so
       <a href="http://releases.llvm.org/8.0.0/docs/LangRef.html#inline-asm-constraint-string">LLVM documentation</a>
       and
@@ -5900,7 +5900,7 @@ volatile (
 
       {#header_open|Input Constraints#}
       <p>
-      Input constraints are still considered to be unstable in Zig, and 
+      Input constraints are still considered to be unstable in Zig, and
       so
       <a href="http://releases.llvm.org/8.0.0/docs/LangRef.html#inline-asm-constraint-string">LLVM documentation</a>
       and
@@ -5919,7 +5919,7 @@ volatile (
       the assembly code. These do not include output or input registers. The special clobber
       value of {#syntax#}"memory"{#endsyntax#} means that the assembly causes writes to
       arbitrary undeclared memory locations - not only the memory pointed to by a declared
-      indirect output. 
+      indirect output.
       </p>
       <p>
       Failure to declare the full set of clobbers for a given inline assembly
@@ -7746,6 +7746,30 @@ test "@setRuntimeSafety" {
       </p>
       {#header_close#}
 
+      {#header_open|@splat#}
+      <pre>{#syntax#}@splat(comptime len: u32, scalar: var) @Vector(len, @typeOf(scalar)){#endsyntax#}</pre>
+      <p>
+      Produces a vector of length {#syntax#}len{#endsyntax#} where each element is the value
+      {#syntax#}scalar{#endsyntax#}:
+      </p>
+      {#code_begin|test#}
+const std = @import("std");
+const assert = std.debug.assert;
+
+test "vector @splat" {
+    const scalar: u32 = 5;
+    const result = @splat(4, scalar);
+    comptime assert(@typeOf(result) == @Vector(4, u32));
+    assert(std.mem.eql(u32, ([4]u32)(result), [_]u32{ 5, 5, 5, 5 }));
+}
+      {#code_end#}
+      <p>
+      {#syntax#}scalar{#endsyntax#} must be an {#link|integer|Integers#}, {#link|bool|Primitive Types#},
+      {#link|float|Floats#}, or {#link|pointer|Pointers#}.
+      </p>
+      {#see_also|Vectors|@shuffle#}
+      {#header_close#}
+
       {#header_open|@sqrt#}
       <pre>{#syntax#}@sqrt(comptime T: type, value: T) T{#endsyntax#}</pre>
       <p>
@@ -9456,8 +9480,8 @@ const c = @cImport({
         <li>Does not support Zig-only pointer attributes such as alignment. Use normal {#link|Pointers#}
         please!</li>
       </ul>
-      <p>When a C pointer is pointing to a single struct (not an array), deference the C pointer to 
-        access to the struct's fields or member data. That syntax looks like 
+      <p>When a C pointer is pointing to a single struct (not an array), deference the C pointer to
+        access to the struct's fields or member data. That syntax looks like
         this: </p>
         <p>{#syntax#}ptr_to_struct.*.struct_member{#endsyntax#}</p>
         <p>This is comparable to doing {#syntax#}->{#endsyntax#} in C.</p>