title: Cannot include Accelerate Header in iOS C++ code
body: <p>I have some code that I want to call vDSP upon. 
  This is a C++ file, in an Xcode project. The main project is in Objective C. 
  Whenever I do </p>
  
  <pre><code>#include &lt;Accelerate/Accelerate.h&gt;  
  </code></pre>
  
  <p>It gives me a lot of errors.</p>
  
  <pre><code>#if defined(__cplusplus)
  #pragma once
  
  #include &lt;Accelerate/Accelerate.h&gt; // &lt;-- error
  #include "oscillator.h"
  
  
  namespace synth {
  class CQBLimitedOscillator : public COscillator
  {
      float dOuts[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
  public:
      CQBLimitedOscillator(void);
      ~CQBLimitedOscillator(void);
  
      // --- init globals
      inline virtual void initGlobalParameters(globalOscillatorParams* pGlobalOscParams)
      {
          // --- always call base class first to store pointer
          COscillator::initGlobalParameters(pGlobalOscParams);
  
          // --- add any QBL specifics here
      }
  
      // -- parallel proqcess 4 sawteeth
      inline void doSawTeeth(float* dOutsIn, float dModulo, float dInc) {
  
          float scalar2Val = 2.0f;
          float scalar1Val = -1.0f;
  
          // -- 2.0f*dValue - 1.0f
          vDSP_vsmsa(dOutsIn, 1, &amp;scalar2Val, &amp;scalar1Val, dOutsIn, 1, 4);
  
      }
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/3lNef.png" alt="Errors"></p>