[Bf-blender-cvs] [16b2b33d019] master: BLI: Add "first" method to MutableSpan and Vector
Hans Goudey
noreply at git.blender.org
Sun Apr 25 22:06:49 CEST 2021
Commit: 16b2b33d0194e79fabca7139658d61701c9d8915
Author: Hans Goudey
Date: Sun Apr 25 15:06:38 2021 -0500
Branches: master
https://developer.blender.org/rB16b2b33d0194e79fabca7139658d61701c9d8915
BLI: Add "first" method to MutableSpan and Vector
This is convenient because having a uniform interface is nice, and
because of the similarity to "last".
Differential Revision: https://developer.blender.org/D11076
===================================================================
M source/blender/blenlib/BLI_span.hh
M source/blender/blenlib/BLI_vector.hh
===================================================================
diff --git a/source/blender/blenlib/BLI_span.hh b/source/blender/blenlib/BLI_span.hh
index c32ba0826df..c3876d4eaf8 100644
--- a/source/blender/blenlib/BLI_span.hh
+++ b/source/blender/blenlib/BLI_span.hh
@@ -661,6 +661,16 @@ template<typename T> class MutableSpan {
return IndexRange(size_);
}
+ /**
+ * Return a reference to the first element in the array. This invokes undefined behavior when the
+ * array is empty.
+ */
+ constexpr T &first() const
+ {
+ BLI_assert(size_ > 0);
+ return data_[0];
+ }
+
/**
* Returns a reference to the last element. This invokes undefined behavior when the array is
* empty.
diff --git a/source/blender/blenlib/BLI_vector.hh b/source/blender/blenlib/BLI_vector.hh
index d08a5c65c52..3ffd5309a04 100644
--- a/source/blender/blenlib/BLI_vector.hh
+++ b/source/blender/blenlib/BLI_vector.hh
@@ -444,7 +444,7 @@ class Vector {
this->append_as(std::move(value));
}
/* This is similar to `std::vector::emplace_back`. */
- template<typename... ForwardValue> void append_as(ForwardValue &&... value)
+ template<typename... ForwardValue> void append_as(ForwardValue &&...value)
{
this->ensure_space_for_one();
this->append_unchecked_as(std::forward<ForwardValue>(value)...);
@@ -486,7 +486,7 @@ class Vector {
{
this->append_unchecked_as(std::move(value));
}
- template<typename... ForwardT> void append_unchecked_as(ForwardT &&... value)
+ template<typename... ForwardT> void append_unchecked_as(ForwardT &&...value)
{
BLI_assert(end_ < capacity_end_);
new (end_) T(std::forward<ForwardT>(value)...);
@@ -668,6 +668,21 @@ class Vector {
return *(end_ - 1);
}
+ /**
+ * Return a reference to the first element in the vector.
+ * This invokes undefined behavior when the vector is empty.
+ */
+ const T &first() const
+ {
+ BLI_assert(this->size() > 0);
+ return *begin_;
+ }
+ T &first()
+ {
+ BLI_assert(this->size() > 0);
+ return *begin_;
+ }
+
/**
* Return how many values are currently stored in the vector.
*/
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