Minor changes across codebase for TravisCI integration to build on

OSX/Clang and Linux/GCC.

.travis.yml

@@ -4,14 +4,31 @@ sudo: true
 matrix:
   include:
     - os: linux
+      env: CXXFLAGS="-std=c++11"
     - os: osx
+      env: CXXFLAGS="-std=c++11"
 
 install:
+  # install latest cmake
+  - |
+    if [ "$TRAVIS_OS_NAME" == "linux" ]; then
+      CMAKE_URL="https://cmake.org/files/v3.11/cmake-3.11.1-Linux-x86_64.tar.gz";
+      mkdir cmake_latest && travis_retry wget --no-check-certificate --quiet -O - ${CMAKE_URL} | tar --strip-components=1 -xz -C cmake_latest;
+      export PATH=$(pwd)/cmake_latest/bin:${PATH};
+    fi
+
+  - |
+    if [ "${TRAVIS_OS_NAME}" = "osx" ]; then
+      brew update;
+      brew uninstall cmake;
+      brew install cmake;
+    fi
+  - which ${CC}
+  - which ${CXX}
+  - which cmake
 
 script:
   - mkdir build
   - cd build
-  - cmake ..
+  - cmake -DBUILD_EXAMPLE=FALSE ..
   - cmake --build .
-
-after_success:

examples/src/RingBuffer.h

@@ -36,6 +36,8 @@
 
 #include <atomic>
 #include <assert.h>
+#include <cstring>
+#include <cstdlib>
 
 template <typename T>
 class RingBufferT 
@@ -65,9 +67,9 @@ class RingBufferT
         size_t allocatedSize = count + 1; // one bin is used to distinguish between the read and write indices when full.
 
         if (mAllocatedSize)
-            mData = (T *)::realloc(mData, allocatedSize * sizeof(T));
+            mData = (T *) std::realloc(mData, allocatedSize * sizeof(T));
         else
-            mData = (T *)::calloc(allocatedSize, sizeof(T));
+            mData = (T *) std::calloc(allocatedSize, sizeof(T));
 
         assert(mData);
 

include/libnyquist/Common.h

@@ -265,19 +265,19 @@ class Dither
 {
     std::uniform_real_distribution<float> distribution;
     std::mt19937 gen;
-    float prev{ 0.0f };
+    float previous;
     DitherType d;
 public:
 
-    Dither(DitherType d) : distribution(-0.5f, +0.5f), d(d) {}
+    Dither(DitherType d) : distribution(-0.5f, +0.5f), d(d), previous(0.f) {}
 
     float operator()(float s)
     {
         if (d == DITHER_TRIANGLE)
         {
             const float value = distribution(gen);
-            s = s + value - prev;
+            s = s + value - previous;
-            prev = value;
+            previous = value;
             return s;
         }
         else return s;