Take advantage of gembox

I think that it is easy to use if it is divided according to the type of library and the general purpose.
It is a subdivision from the previous `default.gembox`.

By type gembox:
- `stdlib`: Add some standard Ruby methods not provided by core.
- `stdlib-ext`: Add some standard Ruby methods that are not provided by `stdlib`.
- `stdlib-io`: Provides `IO`, `File`, `Socket`, `print`, etc. Conflict with `MRB_NO_STDIO`
- `math`: Add a class related to math. Conflict with `MRB_NO_FLOAT`
- `metaprog`: Adds features related to metaprogramming.

Purpose gembox:
- `default.gembox`: Import the same gems as before
- `default-no-stdio.gembox`: Import the` stdlib` and `math`
- `default-no-fpu.gembox`: Import the` stdlib` only

1 files changed, 18 insertions, 0 deletions

diff --git a/mrbgems/stdlib-ext.gembox b/mrbgems/stdlib-ext.gembox
new file mode 100644
index 000000000..2177dca36
--- /dev/null
+++ b/mrbgems/stdlib-ext.gembox
@@ -0,0 +1,18 @@
+# It also works with MRB_NO_STDIO and MRB_NO_FLOAT.
+
+MRuby::GemBox.new do |conf|
+  # Use standard Array#pack, String#unpack methods
+  conf.gem :core => "mruby-pack"
+
+  # Use standard Kernel#sprintf method
+  conf.gem :core => "mruby-sprintf"
+
+  # Use standard Time class
+  conf.gem :core => "mruby-time"
+
+  # Use standard Struct class
+  conf.gem :core => "mruby-struct"
+
+  # Use Random class
+  conf.gem :core => "mruby-random"
+end