From 53fe2bde1a5945350188eebfbe74de7e8065af32 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mos=C3=A8=20Giordano?= <mose@gnu.org>
Date: Tue, 8 Sep 2020 20:46:42 +0100
Subject: [PATCH] Define method for `sincospi`

---
 NEWS.md          |  7 +++++++
 src/math.jl      |  7 +++++++
 test/runtests.jl | 11 +++++++++++
 3 files changed, 25 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index e266dca4..75844aa9 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,6 +1,13 @@
 History of Measurements.jl
 ==========================
 
+v2.4.0 (2020-??-??)
+-------------------
+
+### New features
+
+* New method for `sincospi(::Measurement)`, when `sincospi` is defined.
+
 v2.3.0 (2020-09-08)
 -------------------
 
diff --git a/src/math.jl b/src/math.jl
index 7b3b3814..47d1b6ff 100644
--- a/src/math.jl
+++ b/src/math.jl
@@ -357,6 +357,13 @@ function Base.sincos(a::Measurement)
     return (result(s, c, a), result(c, -s, a))
 end
 
+if isdefined(Base, :sincospi)
+    function Base.sincospi(a::Measurement)
+        s, c = sincospi(a.val)
+        return (result(s, c * pi, a), result(c, -s * pi, a))
+    end
+end
+
 # Tangent: tan, tand, tanh
 
 function Base.tan(a::Measurement)
diff --git a/test/runtests.jl b/test/runtests.jl
index cde55259..7032c4da 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -279,7 +279,18 @@ end
         if isdefined(Base, :sincos)
             # Check we got the sign of derivatives in `sincos` right.
             s, c = @inferred(sincos(a))
+            @test s ≈ sin(a)
+            @test c ≈ cos(a)
             @test s + c ≈ sin(a) + cos(a)
+            @test s - c ≈ sin(a) - cos(a)
+            @test s ^ 2 + c ^ 2 ≈ one(a)
+        end
+        if isdefined(Base, :sincospi)
+            s, c = @inferred(sincospi(a))
+            @test s ≈ sinpi(a)
+            @test c ≈ cospi(a)
+            @test s + c ≈ sinpi(a) + cospi(a)
+            @test s - c ≈ sinpi(a) - cospi(a)
             @test s ^ 2 + c ^ 2 ≈ one(a)
         end
     end