Add C macro

Author: kgryte

lib/node_modules/@stdlib/constants/float64/pi/README.md

@@ -18,7 +18,7 @@ limitations under the License.
 
 -->
 
-# π
+# PI
 
 > The mathematical constant [π][pi].
 
@@ -62,6 +62,60 @@ console.log( PI );
 
 <!-- /.examples -->
 
+<!-- C interface documentation. -->
+
+* * *
+
+<section class="c">
+
+## C APIs
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<!-- C usage documentation. -->
+
+<section class="usage">
+
+### Usage
+
+```c
+#include "stdlib/constants/float64/pi.h"
+```
+
+#### STDLIB_CONSTANT_FLOAT64_PI
+
+Macro for the mathematical constant [π][pi].
+
+</section>
+
+<!-- /.usage -->
+
+<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- C API usage examples. -->
+
+<section class="examples">
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
 <!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
 
 <section class="related">

lib/node_modules/@stdlib/constants/float64/pi/include/stdlib/constants/float64/pi.h

@@ -0,0 +1,27 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2022 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#ifndef STDLIB_CONSTANTS_FLOAT64_PI_H
+#define STDLIB_CONSTANTS_FLOAT64_PI_H
+
+/**
+* Macro for π.
+*/
+#define STDLIB_CONSTANT_FLOAT64_PI 3.141592653589793238
+
+#endif // !STDLIB_CONSTANTS_FLOAT64_PI_H

lib/node_modules/@stdlib/constants/float64/pi/manifest.json

@@ -0,0 +1,36 @@
+{
+  "options": {},
+  "fields": [
+    {
+      "field": "src",
+      "resolve": true,
+      "relative": true
+    },
+    {
+      "field": "include",
+      "resolve": true,
+      "relative": true
+    },
+    {
+      "field": "libraries",
+      "resolve": false,
+      "relative": false
+    },
+    {
+      "field": "libpath",
+      "resolve": true,
+      "relative": false
+    }
+  ],
+  "confs": [
+    {
+      "src": [],
+      "include": [
+        "./include"
+      ],
+      "libraries": [],
+      "libpath": [],
+      "dependencies": []
+    }
+  ]
+}