diff options
Diffstat (limited to 'src/jtutil/array.hh')
| -rw-r--r-- | src/jtutil/array.hh | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/src/jtutil/array.hh b/src/jtutil/array.hh index 0d674bd..fc2060d 100644 --- a/src/jtutil/array.hh +++ b/src/jtutil/array.hh @@ -9,8 +9,8 @@ // // prerequisites: -// <assert.h> -// <stdio.h> // only used for NULL +// <cassert> +// <cstddef> // for NULL // "jt/stdc.h" // "jt/util++.h" // for jtutil::how_many_in_range() // @@ -20,15 +20,13 @@ // contiguous arrays, parameterized by the data type (most commonly float // or double, but could also be bool, int, long double, ...). The // underlying storage can be either supplied by the caller, or allocated -// by new[]. +// by new[]. In the latter case, arbitrary strides are also possible. // // These arrays cannot be copied or passed to functions by value; use // pass by reference instead. (This is a feature, not a bug: passing // large arrays by value would be ++slow, so we don't want to run the // risk of this happing accidentally.) // -// FIXME: Maybe these should be in namespace jtutil::? -// // // Stroustrup ("The C++ Programming Language", 3rd edition, appendix C.7) @@ -58,6 +56,8 @@ //****************************************************************************** +namespace jtutil + { template <typename fp> class array1d { @@ -114,9 +114,12 @@ private: bool we_own_array_; // true ==> array_ --> new[] array which we own // false ==> array --> caller-owns array_ }; + }; // namespace jtutil:: //****************************************************************************** +namespace jtutil + { template <typename fp> class array2d { @@ -138,7 +141,7 @@ public: // FIXME: should we also provide the reverse mapping, i.e. // subscript --> (i,j) ? int subscript_unchecked(int i, int j) const - { return offset_ + stride_i_*i + j; } + { return offset_ + stride_i_*i + stride_j_*j; } int subscript(int i, int j) const { assert( is_valid_subscript(i,j) ); @@ -147,7 +150,7 @@ public: // source line, so an assert() failure message can // pinpoint *which* index is bad assert(posn >= 0); - assert(posn <= N_array_); + assert(posn <= max_subscript_); return posn; } @@ -161,15 +164,19 @@ public: // get access to internal 0-origin 1D storage array // (low-level, dangerous, use with caution!) - int N_array() const { return N_array_; } + // ... semantics of N_array() may not be what you want + // if strides specify noncontiguous storage + int N_array() const { return max_subscript_+1; } fp* get_array() const { return array_; } // constructor, destructor - // constructor initializes all array elements to fp(0.0) + // ... constructor initializes all array elements to fp(0.0) + // ... omitted strides default to C storage order array2d(int min_i_in, int max_i_in, int min_j_in, int max_j_in, - fp *array_in = NULL); // caller-provided storage array + fp *array_in = NULL, // caller-provided storage array // if non-NULL + int stride_i_in = 0, int stride_j_in = 0); ~array2d(); private: @@ -188,20 +195,23 @@ private: // subscripting info // n.b. put this next in class so it should be in the same // cpu cache line as array_ ==> faster array access - int offset_, stride_i_; + int offset_, stride_i_, stride_j_; // min/max array bounds - int N_array_; const int min_i_, max_i_; const int min_j_, max_j_; + int max_subscript_; // n.b. put this at end of class since performance doesn't matter bool we_own_array_; // true ==> array_ --> new[] array which we own // false ==> array --> caller-owns array_ }; + }; // namespace jtutil:: //****************************************************************************** +namespace jtutil + { template <typename fp> class array3d { @@ -290,9 +300,12 @@ private: bool we_own_array_; // true ==> array_ --> new[] array which we own // false ==> array --> caller-owns array_ }; + }; // namespace jtutil:: //****************************************************************************** +namespace jtutil + { template <typename fp> class array4d { @@ -393,3 +406,4 @@ private: bool we_own_array_; // true ==> array_ --> new[] array which we own // false ==> array --> caller-owns array_ }; + }; // namespace jtutil:: |