add wip span type and new file2 interface and fstream impl.

testing was very minimal

CMakeLists.txt

@@ -3,6 +3,8 @@ cmake_minimum_required(VERSION 3.9 FATAL_ERROR)
 project(solanaceae)
 
 add_library(solanaceae_util
+	./solanaceae/util/span.hpp
+
 	./solanaceae/util/utils.hpp
 	./solanaceae/util/utils.cpp
 
@@ -20,3 +22,16 @@ target_compile_features(solanaceae_util PUBLIC cxx_std_17)
 #target_link_libraries(solanaceae_util PUBLIC
 #)
 
+########################################
+
+add_library(solanaceae_file2
+	./solanaceae/file/file2.hpp
+	./solanaceae/file/file2_std.hpp
+	./solanaceae/file/file2_std.cpp
+)
+
+target_include_directories(solanaceae_file2 PUBLIC .)
+target_compile_features(solanaceae_file2 PUBLIC cxx_std_17)
+target_link_libraries(solanaceae_file2 PUBLIC
+	solanaceae_util
+)