Add support for compiling rxcpp with -fno-exceptions (#456)

* Minor compilation/test fixes for compiling on android

Change-Id: Id623455d32e9323355744a240c2813d0411d1dac

* Rx: Add support for compiling code without exceptions (-fno-exceptions)

std::exception_ptr usage is replaced with rxcpp::util::error_ptr
which will typedef to std::exception_ptr when exceptions are enabled.

When exceptions are disabled this will typedef to an internal error
type that can retain the "what" error message.

Additionally std::current_exception() and similar usages are replaced
with rxu::current_exception which uses error_ptr instead.

Lastly all try/catch/throw keywords are replaced with either
RXCPP_TRY, RXCPP_CATCH, rxu::throw_exception or similar.

Note that try/catch/throw keywords cause a compilation error with
-fno-exceptions. Trying to access most of the std::*exception* functions
will call std::terminate at runtime.

Tests using exceptions must be disabled by passing --nothrow to the
check2 test runner.

Change-Id: I0b95ae2e323653a17c3b733d165ecf87a014c315

* update to catch2 and add RX_USE_EXCEPTIONS cmake option

* fix bugs in doxygen examples

* replace [[noreturn]] with RXCPP_NORETURN

* removes support for VS 2013

2 files changed, 23 insertions, 4 deletions

diff --git a/projects/CMake/CMakeLists.txt b/projects/CMake/CMakeLists.txt
index 542a91a..d15c57f 100644
--- a/projects/CMake/CMakeLists.txt
+++ b/projects/CMake/CMakeLists.txt
@@ -59,6 +59,7 @@ set(RX_SOURCES
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-ref_count.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-repeat.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-replay.hpp
+   ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-retry-repeat-common.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-retry.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-sample_time.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-scan.hpp
@@ -83,13 +84,16 @@ set(RX_SOURCES
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-with_latest_from.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-window.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-window_time.hpp
+   ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-window_toggle.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-window_time_count.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/operators/rx-zip.hpp
+   ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-composite_exception.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-connectable_observable.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-coordination.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-coroutine.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-grouped_observable.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-includes.hpp
+   ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-lite.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-notification.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-observable.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/rx-observer.hpp
@@ -114,6 +118,7 @@ set(RX_SOURCES
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/schedulers/rx-virtualtime.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/sources/rx-create.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/sources/rx-defer.hpp
+   ${RXCPP_DIR}/Rx/v2/src/rxcpp/sources/rx-empty.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/sources/rx-error.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/sources/rx-interval.hpp
    ${RXCPP_DIR}/Rx/v2/src/rxcpp/sources/rx-iterate.hpp
diff --git a/projects/CMake/shared.cmake b/projects/CMake/shared.cmake
index ac0d09c..f7f7a31 100644
--- a/projects/CMake/shared.cmake
+++ b/projects/CMake/shared.cmake
@@ -1,5 +1,7 @@
 FIND_PACKAGE(Threads)
 
+option(RX_USE_EXCEPTIONS "Use C++ exceptions" ON)
+
 # define some compiler settings
 
 MESSAGE( STATUS "CMAKE_CXX_COMPILER_ID: " ${CMAKE_CXX_COMPILER_ID} )
@@ -13,13 +15,21 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
         -Wno-error=unused-command-line-argument
         -ftemplate-depth=1024
         )
+    if (NOT RX_USE_EXCEPTIONS)
+        MESSAGE( STATUS "no exceptions" )
+        list(APPEND RX_COMPILE_OPTIONS -fno-exceptions)
+    endif()
 elseif (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
     MESSAGE( STATUS "gnu compiler version: " ${CMAKE_CXX_COMPILER_VERSION} )
     MESSAGE( STATUS "using gnu settings" )
     set(RX_COMPILE_OPTIONS
         -Wall -Wextra -Werror -Wunused
         )
-elseif (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
+    if (NOT RX_USE_EXCEPTIONS)
+        MESSAGE( STATUS "no exceptions" )
+        list(APPEND RX_COMPILE_OPTIONS -fno-exceptions)
+    endif()
+  elseif (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
     MESSAGE( STATUS "msvc compiler version: " ${CMAKE_CXX_COMPILER_VERSION} )
     MESSAGE( STATUS "using msvc settings" )
     set(RX_COMPILE_OPTIONS
@@ -29,9 +39,13 @@ elseif (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
         /bigobj
         /DUNICODE /D_UNICODE # it is a new millenium
         )
+    if (NOT RX_USE_EXCEPTIONS)
+        MESSAGE( STATUS "no exceptions" )
+        list(APPEND RX_COMPILE_OPTIONS /EHs-c-)
+    endif()
     if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS "19.0.23506.0")
-        set(RX_COMPILE_OPTIONS
-            ${RX_COMPILE_OPTIONS}
+        MESSAGE( STATUS "with coroutines" )
+        list(APPEND RX_COMPILE_OPTIONS
             /await # enable coroutines
             )
     endif()
@@ -54,4 +68,4 @@ set(RX_COMPILE_FEATURES
 
 set(IX_SRC_DIR ${RXCPP_DIR}/Ix/CPP/src)
 set(RX_SRC_DIR ${RXCPP_DIR}/Rx/v2/src)
-set(RX_CATCH_DIR ${RXCPP_DIR}/ext/catch/include)
+set(RX_CATCH_DIR ${RXCPP_DIR}/ext/catch/single_include/catch2)