fixed some warnings in debug mode (GCC/Linux)

include/audacity/Types.h

@@ -45,6 +45,7 @@
 #include <algorithm>
 #include <wx/string.h>
 #include <wx/arrstr.h>
+#include <type_traits>
 
 // ----------------------------------------------------------------------------
 // TODO:  I'd imagine this header may be replaced by other public headers. But,
@@ -90,7 +91,7 @@ public:
 
    size_t as_size_t() const {
       wxASSERT(value >= 0);
-      wxASSERT(value <= std::numeric_limits<size_t>::max());
+      wxASSERT(static_cast<std::make_unsigned<type>::type>(value) <= std::numeric_limits<size_t>::max());
       return value;
    }
 

src/BatchCommands.cpp

@@ -704,7 +704,7 @@ bool MacroCommands::ApplyEffectCommand(
    const wxString & command, const wxString & params,
    const CommandContext & Context)
 {
-   (void*)&command;//compiler food.
+   static_cast<void>(command);//compiler food.
 
    //Possibly end processing here, if in batch-debug
    if( ReportAndSkip(friendlyCommand, params))

src/SampleFormat.cpp

@@ -90,7 +90,7 @@ void ReverseSamples(samplePtr dst, sampleFormat format,
    samplePtr first = dst + start * size;
    samplePtr last = dst + (start + len - 1) * size;
    enum : size_t { fixedSize = SAMPLE_SIZE(floatSample) };
-   wxASSERT(size <= fixedSize);
+   wxASSERT(static_cast<size_t>(size) <= fixedSize);
    char temp[fixedSize];
    while (first < last) {
       memcpy(temp, first, size);