kraken: move 'Order' definition to 'book'

I think it makes more sense to centralise these important types in the
`book` library.

src/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_executable(kraken kraken.cc)
 target_link_libraries(kraken PRIVATE common_options)
 
+add_subdirectory(book)
 add_subdirectory(csv)
 add_subdirectory(parse)
 add_subdirectory(utils)
@@ -8,6 +9,7 @@ add_subdirectory(utils)
 configure_file(config.h.in config.h)
 
 target_link_libraries(kraken PRIVATE
+  book
   csv
   parse
 )

src/book/CMakeLists.txt

@@ -0,0 +1,10 @@
+add_library(book STATIC
+  order.cc
+  order.hh
+)
+
+target_link_libraries(book PRIVATE
+  utils
+)
+
+target_link_libraries(book PRIVATE common_options)

src/book/order.hh

@@ -5,7 +5,7 @@
 
 #include "utils/strong-type.hh"
 
-namespace kraken::parse {
+namespace kraken {
 
 /// Which side the order is on.
 enum class Side {
@@ -68,4 +68,4 @@ struct FlushOrder {
 
 using Order = std::variant<TradeOrder, CancelOrder, FlushOrder>;
 
-} // namespace kraken::parse
+} // namespace kraken

src/parse/CMakeLists.txt

@@ -1,11 +1,10 @@
 add_library(parse STATIC
-  order.cc
-  order.hh
   parse.cc
   parse.hh
 )
 
 target_link_libraries(parse PRIVATE
+  book
   csv
   utils
 )

src/parse/parse.hh

@@ -4,7 +4,7 @@
 #include <stdexcept>
 #include <vector>
 
-#include "order.hh"
+#include "book/order.hh"
 
 namespace kraken::parse {
 

tests/unit/parse.cc

@@ -6,6 +6,7 @@
 #include "parse/parse.hh"
 
 // Allow namespace pollution in tests for convenience
+using namespace kraken;
 using namespace kraken::parse;
 
 namespace {