add within

src/meson.build

@@ -1,3 +1,4 @@
 inc += include_directories('.')
 
 subdir('string')
+subdir('range')

src/range/meson.build

@@ -0,0 +1,14 @@
+headers = ['range.hpp']
+sources = ['range.cpp']
+
+lib = library(
+  'range',
+  include_directories : inc,
+  install : true,
+  sources: [headers, sources]
+)
+
+range_dep = declare_dependency(
+  include_directories: inc,
+  link_with: lib
+)

src/range/range.cpp

@@ -0,0 +1,5 @@
+#include "range.hpp"
+
+namespace hack
+{
+}

src/range/range.hpp

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace hack
+{
+  template<typename T, typename... Args>
+  bool within(T min, T max, Args... args)
+  {
+    return ((min <= args && max >= args) && ...);
+    // 1, 5, 2, 3, 4
+    // ( (1 <= 2 && 5 >= 2) && (1 <= 3 && 5 >= 3) && (1 <= 4 && 5 >= 4) )
+  }
+}