From 910415e6e0e434348a1f577bfb56e36b5e7089eb Mon Sep 17 00:00:00 2001
From: John Travers <jtravs@gmail.com>
Date: Tue, 13 Aug 2019 13:56:00 +0100
Subject: [PATCH] fix #44 (#45)

---
 src/Cubature.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Cubature.jl b/src/Cubature.jl
index ee60df9..bf1a8e7 100644
--- a/src/Cubature.jl
+++ b/src/Cubature.jl
@@ -37,7 +37,7 @@ const FAILURE = Int32(1)
 # type to distinguish cubature error codes from thrown exceptions
 struct NoError <: Exception end # used for integrand_error when nothing thrown
 
-struct IntegrandData{F}
+mutable struct IntegrandData{F}
     integrand_func::F
     integrand_error::Any
     IntegrandData(f::F) where{F} = new{F}(f, NoError())