Hi, everyone. Correct me if I’m wrong, please: I understand that an Array is implemented via a MemoryRef which contains a Memory object, with supertype DenseArray. When an array is created, some memory is allocated. MemoryRef contains the address and Memory contains the elements. This Memory objec…

[image] pmc4: should I use Memory instead of Array directly? Memory is one dimensional, if you need to use multidimensional arrays that won’t cut it. FixedSizeArrays.jl, mentioned above, provides the linear algebra structure around Memory, similarly to Array, with the additional constraint t…

[image] pmc4: However, I’d like to understand the difference of using Memory vs Array, as I stated above. Not just using a package that does it, if this makes sense. Memory is a one dimensional contiguous chunk of memory, lacking the linear algebra structure Array is a multidimensional, resi…

Memory is a very simple heap-allocated 1D buffer, used as a backend for a variety of data structures. Most of the Array API isn’t implemented for Memory, so you can’t use it as a substitute for Vector. The Memory backing a Vector doesn’t even mirror it: julia> x = [1] 1-element Vector{Int64}: 1 j…

[image] pmc4: Is there any performance reason to use them or any reason to avoid them? Memory is slightly friendlier to the compiler optimizer. An example is how the heap allocation can currently be replaced with a stack allocation in more cases with Memory than with Vector. Related examples: …

As the others said, Memory is a built-in that julia uses for a fixed size buffer. Memory has an identity (i.e. like it were defined as mutable struct), but is immutable (all fields are const). The allocation underlying the Memory’s memory typically has a lifetime tied to the Memory’s lifetime. Thi…

[image] pmc4: However, I’d like to understand the difference of using Memory vs Array, as I stated above. Not just using a package that does it, if this makes sense. With Array there is an indirection as you have noted. I.e. an additional pointer to be followed in the MemoryRef struct. In loo…

[image] sgaure: With Array there is an indirection as you have noted. I.e. an additional pointer to be followed in the MemoryRef struct Accessing data through Memory and Array has the same number of indirections / pointers to chase. Arrays do not access their data through the underlying Memor…

[image] foobar_lv2: Accessing data through Memory and Array has the same number of indirections / pointers to chase. Arrays do not access their data through the underlying Memory (a.ref.mem) but instead through their Memory-ref a.ref.ptr_or_offset, which directly points at the buffer. yes, bu…

Is there any advantage of directly using `Memory{T}` over a traditional Array?

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digital_carver March 6, 2026, 9:01am 2

FixedSizeArrays.jl uses Memory while conforming to the array interface (and giving you LTS 1.10 compatibility): [ANN] FixedSizeArrays.jl: What Array probably should have been

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Is there any advantage of directly using `Memory{T}` over a traditional Array?

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