X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=src%2Fapi%2FBamIndex.h;h=067244ec2d2fd845458d7868dbee553771388be7;hb=2e1822c9ed231b25fd474117a01a1492d4209fa4;hp=b202e921ff9d13c56796469abef5550486241430;hpb=2e049ed7f28881bce09653e60f5aea54bfd7afbf;p=bamtools.git

diff --git a/src/api/BamIndex.h b/src/api/BamIndex.h
index b202e92..067244e 100644
--- a/src/api/BamIndex.h
+++ b/src/api/BamIndex.h
@@ -78,14 +78,14 @@ class API_EXPORT BamIndex {
 
     // internal methods
     protected:
-        void SetErrorString(const std::string& where, const std::string& what) {
+        void SetErrorString(const std::string& where, const std::string& what) const {
             m_errorString = where + ": " + what;
         }
 
     // data members
     protected:
         Internal::BamReaderPrivate* m_reader; // copy, not owned
-        std::string m_errorString;
+        mutable std::string m_errorString;
 };
 
 } // namespace BamTools