Macro "R" definition?

We’ve been using SDK 3.6.12 for awhile with XCode 10. Now upgrading to SDK 3.7.1 with XCode 12.2 (we’ve been using XCode 12.2 for awhile with other software, so that is not new). Set up our XCode build settings to match the examples in the SDK (standard C++ library C++11; C++ dialect C++14). Getting some initial compilation errors in VST SDK sw. Searching has not revealed a solution yet. One example is

writer.write (R"(<?xml version="1.0" encoding="UTF-8"?>)");

The R macro (?) is undefined. Any ideas where “R” would normally be defined? … if we can identify that, it may explain the other errors we are seeing.

This is a raw string literal: Looks like you are not compiling with c++11 mode.

Thanks, I’ll check that out.