message: Document assumptions about C++ compiler
diff: # error "Bitcoin cannot be compiled without assertions."
  #endif
  +// Assumption: We assume a C++11 (ISO/IEC 14882:2011) compiler (minimum requirement).
  +// Example(s): We assume the presence of C++11 features everywhere :-)
  +// Note: MSVC does not report the expected __cplusplus value due to legacy
  +// reasons.
  +#if !defined(_MSC_VER)
  +// ISO Standard C++11 [cpp.predefined]p1:
  +// "The name __cplusplus is defined to the value 201103L when compiling a C++
  +// translation unit."
  +static_assert(__cplusplus >= 201103L, "C++11 standard assumed");
  +#endif
  +
  // Assumption: We assume the floating-point types to fulfill the requirements of
  // IEC 559 (IEEE 754) standard.
  // Example(s): Floating-point division by zero in ConnectBlock, CreateTransaction
  