From 7b5d3e01c052fabf379db2509598a30224ba8a2b Mon Sep 17 00:00:00 2001
From: Vitaly Zaitsev <vitaly@easycoding.org>
Date: Tue, 4 Feb 2020 09:02:19 +0100
Subject: [PATCH] Find and use packaged version of expected header-only
 library.

Enabled by default when `DESKTOP_APP_USE_PACKAGED` is used. Can be
overriden by `-DDESKTOP_APP_USE_PACKAGED_EXPECTED:BOOL=OFF`.

Signed-off-by: Vitaly Zaitsev <vitaly@easycoding.org>
---
 external/expected/CMakeLists.txt | 13 +++++++++----
 external/variant/CMakeLists.txt  | 15 +++++++++++----
 variables.cmake                  |  2 ++
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/external/expected/CMakeLists.txt b/external/expected/CMakeLists.txt
index 53ec233..e44617a 100644
--- a/external/expected/CMakeLists.txt
+++ b/external/expected/CMakeLists.txt
@@ -7,7 +7,12 @@
 add_library(external_expected INTERFACE IMPORTED GLOBAL)
 add_library(desktop-app::external_expected ALIAS external_expected)
 
-target_include_directories(external_expected SYSTEM
-INTERFACE
-    ${third_party_loc}/expected/include
-)
+if (DESKTOP_APP_USE_PACKAGED_EXPECTED)
+    find_package(tl-expected CONFIG REQUIRED)
+    target_link_libraries(external_expected INTERFACE tl::expected)
+else()
+    target_include_directories(external_expected SYSTEM
+    INTERFACE
+        ${third_party_loc}/expected/include
+    )
+endif()
diff --git a/external/variant/CMakeLists.txt b/external/variant/CMakeLists.txt
index 5b5beef..a198f90 100644
--- a/external/variant/CMakeLists.txt
+++ b/external/variant/CMakeLists.txt
@@ -7,7 +7,14 @@
 add_library(external_variant INTERFACE IMPORTED GLOBAL)
 add_library(desktop-app::external_variant ALIAS external_variant)
 
-target_include_directories(external_variant SYSTEM
-INTERFACE
-    ${third_party_loc}/variant/include
-)
+if (DESKTOP_APP_USE_PACKAGED_VARIANT)
+    find_path(VARIANT_INCLUDE_DIRS mapbox/variant.hpp)
+    if (NOT VARIANT_INCLUDE_DIRS)
+        message(FATAL_ERROR "Packaged version of mapbox-variant library not found!")
+    endif()
+else()
+    target_include_directories(external_variant SYSTEM
+    INTERFACE
+        ${third_party_loc}/variant/include
+    )
+endif()
diff --git a/variables.cmake b/variables.cmake
index 9d3b075..c288f51 100644
--- a/variables.cmake
+++ b/variables.cmake
@@ -23,6 +23,8 @@ endif()
 
 option(DESKTOP_APP_DISABLE_CRASH_REPORTS "Disable crash report generation." ${DESKTOP_APP_USE_PACKAGED})
 option(DESKTOP_APP_USE_PACKAGED_RLOTTIE "Find rlottie using CMake instead of bundled one." ${DESKTOP_APP_USE_PACKAGED})
+option(DESKTOP_APP_USE_PACKAGED_EXPECTED "Find expected using CMake instead of bundled one." ${DESKTOP_APP_USE_PACKAGED})
+option(DESKTOP_APP_USE_PACKAGED_VARIANT "Find mapbox-variant using CMake instead of bundled one." ${DESKTOP_APP_USE_PACKAGED})
 option(DESKTOP_APP_USE_PACKAGED_FONTS "Use preinstalled fonts instead of bundled one." ${DESKTOP_APP_USE_PACKAGED})
 
 option(DESKTOP_APP_ENABLE_IPO_OPTIMIZATIONS "Enable IPO build optimizations." OFF)