From 1ab31e6c197b68b7ea4f35fd0feb2fd49a84e3ed Mon Sep 17 00:00:00 2001
From: Guilhem Lavaux <guilhem.lavaux@gmail.com>
Date: Thu, 12 Feb 2015 08:50:07 +0100
Subject: [PATCH] hdf5_read_array now supports array witout resize.

---
 src/hdf5_array.hpp | 44 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/src/hdf5_array.hpp b/src/hdf5_array.hpp
index c6ce5c9..318181f 100644
--- a/src/hdf5_array.hpp
+++ b/src/hdf5_array.hpp
@@ -180,7 +180,49 @@ namespace CosmoTool {
       return boost::extents;
     }
   };
+  
+  
+  template<typename Array> class array_has_resize {
+    struct Fallback { int resize; };
+    struct Derived: Array, Fallback {};
 
+    typedef char yes[1];
+    typedef char no[2];
+
+    template<typename U, U> struct Check;
+
+    template<typename U> 
+    static yes& func(Check<int Fallback::*, &U::resize> *);
+
+    template<typename U>
+    static no& func(...);
+  public:
+    typedef array_has_resize type;
+    enum { value = sizeof(func<Derived>(0)) == sizeof(no) };
+  };
+
+  
+
+  template<typename ArrayType>
+    typename boost::enable_if<
+      array_has_resize<ArrayType> 
+  >::type 
+    hdf5_resize_array(ArrayType& data, std::vector<hsize_t>& dims) {
+    data.resize(
+        hdf5_extent_gen<ArrayType::dimensionality>::build(dims.data())
+    );
+  }
+
+  template<typename ArrayType>
+    typename boost::disable_if<
+      array_has_resize<ArrayType> 
+  >::type 
+    hdf5_resize_array(ArrayType& data, std::vector<hsize_t>& dims) {
+    for (long i = 0; i < data.num_dimensions(); i++) {
+        assert (data.shape()[i] == dims[i]);
+    }
+  }
+  
   template<typename ArrayType, typename hdf5_data_type>
   void hdf5_read_array(H5::CommonFG& fg, const std::string& data_set_name, 
                        ArrayType& data, 
@@ -196,7 +238,7 @@ namespace CosmoTool {
         }
             
       dataspace.getSimpleExtentDims(dimensions.data());
-      data.resize(hdf5_extent_gen<ArrayType::dimensionality>::build(dimensions.data()));
+      hdf5_resize_array(data, dimensions);
       dataset.read(data.data(), datatype);
   }