Why can't I use Marshal.SizeOf() to calculate the size of an instance of type ValueTuple?











up vote
0
down vote

favorite












Why does the following code:



   ValueTuple<double, double> origin = (0.0, 0.0);

Console.WriteLine($"Size of ValueTuple<double, double>: {Marshal.SizeOf(origin)}");



throw System.ArgumentException: 'Type
'System.ValueTuple`2[System.Double,System.Double]' cannot be marshaled
as an unmanaged structure; no meaningful size or offset can be computed.'











share|improve this question




















  • 2




    Sounds pretty definitive to me. what is the actual problem you are trying to solve
    – TheGeneral
    Nov 20 at 0:54












  • Unless you're actually planning to send something into the unmanaged world, Marshal.SizeOf may as well be replaced with Random.Next. It tells you then size of the unmanaged representation of the type, which is only meaningful if you'll create such a thing, and as it says here, you can't create an unmanaged representation of a valuetuple.
    – Damien_The_Unbeliever
    Nov 20 at 7:10










  • I'm not attempting to marshal a ValueTuple to unmanaged code. However, the actual motivation is probably controversial. I have my own implementation of IList<T> called BigList<T> that uses a pool of buffers that are small enough to stay off the Large Object Heap. This requires knowing the size in bytes of T. I've been using Marshal.SizeOf() for this purpose.
    – mikevg
    Nov 20 at 16:00






  • 1




    To avoid LOH limit, you need managed size of T, not marshalled size of T returned by Marshall.SizeOf(), which can be different (What’s the difference? sizeof and Marshal.SizeOf). Some workarounds here and here. Also remember that array size is not just size_of_T * array_length but array needs some additional memory (to store array length, dimension, object headers) which is also runtime-dependent.
    – Ňuf
    Nov 20 at 21:38










  • I knew that the "managed" and "unmanaged" sizes of T could be different but my situation is limited to simple value types T and my implementation is not particularly sensitive to errors using Marshal.SizeOf(). My buffers are actually arrays of T and I can tell if they end up on LOH. What I was missing is that I can Emit OpCodes.Sizeof to get the "managed" size. This fixes my problem and I can now create BigList<T> where T is a ValueTuple. Thanks!
    – mikevg
    Nov 21 at 1:14

















up vote
0
down vote

favorite












Why does the following code:



   ValueTuple<double, double> origin = (0.0, 0.0);

Console.WriteLine($"Size of ValueTuple<double, double>: {Marshal.SizeOf(origin)}");



throw System.ArgumentException: 'Type
'System.ValueTuple`2[System.Double,System.Double]' cannot be marshaled
as an unmanaged structure; no meaningful size or offset can be computed.'











share|improve this question




















  • 2




    Sounds pretty definitive to me. what is the actual problem you are trying to solve
    – TheGeneral
    Nov 20 at 0:54












  • Unless you're actually planning to send something into the unmanaged world, Marshal.SizeOf may as well be replaced with Random.Next. It tells you then size of the unmanaged representation of the type, which is only meaningful if you'll create such a thing, and as it says here, you can't create an unmanaged representation of a valuetuple.
    – Damien_The_Unbeliever
    Nov 20 at 7:10










  • I'm not attempting to marshal a ValueTuple to unmanaged code. However, the actual motivation is probably controversial. I have my own implementation of IList<T> called BigList<T> that uses a pool of buffers that are small enough to stay off the Large Object Heap. This requires knowing the size in bytes of T. I've been using Marshal.SizeOf() for this purpose.
    – mikevg
    Nov 20 at 16:00






  • 1




    To avoid LOH limit, you need managed size of T, not marshalled size of T returned by Marshall.SizeOf(), which can be different (What’s the difference? sizeof and Marshal.SizeOf). Some workarounds here and here. Also remember that array size is not just size_of_T * array_length but array needs some additional memory (to store array length, dimension, object headers) which is also runtime-dependent.
    – Ňuf
    Nov 20 at 21:38










  • I knew that the "managed" and "unmanaged" sizes of T could be different but my situation is limited to simple value types T and my implementation is not particularly sensitive to errors using Marshal.SizeOf(). My buffers are actually arrays of T and I can tell if they end up on LOH. What I was missing is that I can Emit OpCodes.Sizeof to get the "managed" size. This fixes my problem and I can now create BigList<T> where T is a ValueTuple. Thanks!
    – mikevg
    Nov 21 at 1:14















up vote
0
down vote

favorite









up vote
0
down vote

favorite











Why does the following code:



   ValueTuple<double, double> origin = (0.0, 0.0);

Console.WriteLine($"Size of ValueTuple<double, double>: {Marshal.SizeOf(origin)}");



throw System.ArgumentException: 'Type
'System.ValueTuple`2[System.Double,System.Double]' cannot be marshaled
as an unmanaged structure; no meaningful size or offset can be computed.'











share|improve this question















Why does the following code:



   ValueTuple<double, double> origin = (0.0, 0.0);

Console.WriteLine($"Size of ValueTuple<double, double>: {Marshal.SizeOf(origin)}");



throw System.ArgumentException: 'Type
'System.ValueTuple`2[System.Double,System.Double]' cannot be marshaled
as an unmanaged structure; no meaningful size or offset can be computed.'








c# .net valuetuple






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 20 at 0:55









TheGeneral

26.4k63163




26.4k63163










asked Nov 20 at 0:54









mikevg

234




234








  • 2




    Sounds pretty definitive to me. what is the actual problem you are trying to solve
    – TheGeneral
    Nov 20 at 0:54












  • Unless you're actually planning to send something into the unmanaged world, Marshal.SizeOf may as well be replaced with Random.Next. It tells you then size of the unmanaged representation of the type, which is only meaningful if you'll create such a thing, and as it says here, you can't create an unmanaged representation of a valuetuple.
    – Damien_The_Unbeliever
    Nov 20 at 7:10










  • I'm not attempting to marshal a ValueTuple to unmanaged code. However, the actual motivation is probably controversial. I have my own implementation of IList<T> called BigList<T> that uses a pool of buffers that are small enough to stay off the Large Object Heap. This requires knowing the size in bytes of T. I've been using Marshal.SizeOf() for this purpose.
    – mikevg
    Nov 20 at 16:00






  • 1




    To avoid LOH limit, you need managed size of T, not marshalled size of T returned by Marshall.SizeOf(), which can be different (What’s the difference? sizeof and Marshal.SizeOf). Some workarounds here and here. Also remember that array size is not just size_of_T * array_length but array needs some additional memory (to store array length, dimension, object headers) which is also runtime-dependent.
    – Ňuf
    Nov 20 at 21:38










  • I knew that the "managed" and "unmanaged" sizes of T could be different but my situation is limited to simple value types T and my implementation is not particularly sensitive to errors using Marshal.SizeOf(). My buffers are actually arrays of T and I can tell if they end up on LOH. What I was missing is that I can Emit OpCodes.Sizeof to get the "managed" size. This fixes my problem and I can now create BigList<T> where T is a ValueTuple. Thanks!
    – mikevg
    Nov 21 at 1:14
















  • 2




    Sounds pretty definitive to me. what is the actual problem you are trying to solve
    – TheGeneral
    Nov 20 at 0:54












  • Unless you're actually planning to send something into the unmanaged world, Marshal.SizeOf may as well be replaced with Random.Next. It tells you then size of the unmanaged representation of the type, which is only meaningful if you'll create such a thing, and as it says here, you can't create an unmanaged representation of a valuetuple.
    – Damien_The_Unbeliever
    Nov 20 at 7:10










  • I'm not attempting to marshal a ValueTuple to unmanaged code. However, the actual motivation is probably controversial. I have my own implementation of IList<T> called BigList<T> that uses a pool of buffers that are small enough to stay off the Large Object Heap. This requires knowing the size in bytes of T. I've been using Marshal.SizeOf() for this purpose.
    – mikevg
    Nov 20 at 16:00






  • 1




    To avoid LOH limit, you need managed size of T, not marshalled size of T returned by Marshall.SizeOf(), which can be different (What’s the difference? sizeof and Marshal.SizeOf). Some workarounds here and here. Also remember that array size is not just size_of_T * array_length but array needs some additional memory (to store array length, dimension, object headers) which is also runtime-dependent.
    – Ňuf
    Nov 20 at 21:38










  • I knew that the "managed" and "unmanaged" sizes of T could be different but my situation is limited to simple value types T and my implementation is not particularly sensitive to errors using Marshal.SizeOf(). My buffers are actually arrays of T and I can tell if they end up on LOH. What I was missing is that I can Emit OpCodes.Sizeof to get the "managed" size. This fixes my problem and I can now create BigList<T> where T is a ValueTuple. Thanks!
    – mikevg
    Nov 21 at 1:14










2




2




Sounds pretty definitive to me. what is the actual problem you are trying to solve
– TheGeneral
Nov 20 at 0:54






Sounds pretty definitive to me. what is the actual problem you are trying to solve
– TheGeneral
Nov 20 at 0:54














Unless you're actually planning to send something into the unmanaged world, Marshal.SizeOf may as well be replaced with Random.Next. It tells you then size of the unmanaged representation of the type, which is only meaningful if you'll create such a thing, and as it says here, you can't create an unmanaged representation of a valuetuple.
– Damien_The_Unbeliever
Nov 20 at 7:10




Unless you're actually planning to send something into the unmanaged world, Marshal.SizeOf may as well be replaced with Random.Next. It tells you then size of the unmanaged representation of the type, which is only meaningful if you'll create such a thing, and as it says here, you can't create an unmanaged representation of a valuetuple.
– Damien_The_Unbeliever
Nov 20 at 7:10












I'm not attempting to marshal a ValueTuple to unmanaged code. However, the actual motivation is probably controversial. I have my own implementation of IList<T> called BigList<T> that uses a pool of buffers that are small enough to stay off the Large Object Heap. This requires knowing the size in bytes of T. I've been using Marshal.SizeOf() for this purpose.
– mikevg
Nov 20 at 16:00




I'm not attempting to marshal a ValueTuple to unmanaged code. However, the actual motivation is probably controversial. I have my own implementation of IList<T> called BigList<T> that uses a pool of buffers that are small enough to stay off the Large Object Heap. This requires knowing the size in bytes of T. I've been using Marshal.SizeOf() for this purpose.
– mikevg
Nov 20 at 16:00




1




1




To avoid LOH limit, you need managed size of T, not marshalled size of T returned by Marshall.SizeOf(), which can be different (What’s the difference? sizeof and Marshal.SizeOf). Some workarounds here and here. Also remember that array size is not just size_of_T * array_length but array needs some additional memory (to store array length, dimension, object headers) which is also runtime-dependent.
– Ňuf
Nov 20 at 21:38




To avoid LOH limit, you need managed size of T, not marshalled size of T returned by Marshall.SizeOf(), which can be different (What’s the difference? sizeof and Marshal.SizeOf). Some workarounds here and here. Also remember that array size is not just size_of_T * array_length but array needs some additional memory (to store array length, dimension, object headers) which is also runtime-dependent.
– Ňuf
Nov 20 at 21:38












I knew that the "managed" and "unmanaged" sizes of T could be different but my situation is limited to simple value types T and my implementation is not particularly sensitive to errors using Marshal.SizeOf(). My buffers are actually arrays of T and I can tell if they end up on LOH. What I was missing is that I can Emit OpCodes.Sizeof to get the "managed" size. This fixes my problem and I can now create BigList<T> where T is a ValueTuple. Thanks!
– mikevg
Nov 21 at 1:14






I knew that the "managed" and "unmanaged" sizes of T could be different but my situation is limited to simple value types T and my implementation is not particularly sensitive to errors using Marshal.SizeOf(). My buffers are actually arrays of T and I can tell if they end up on LOH. What I was missing is that I can Emit OpCodes.Sizeof to get the "managed" size. This fixes my problem and I can now create BigList<T> where T is a ValueTuple. Thanks!
– mikevg
Nov 21 at 1:14



















active

oldest

votes











Your Answer






StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53384726%2fwhy-cant-i-use-marshal-sizeof-to-calculate-the-size-of-an-instance-of-type-va%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Stack Overflow!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53384726%2fwhy-cant-i-use-marshal-sizeof-to-calculate-the-size-of-an-instance-of-type-va%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

404 Error Contact Form 7 ajax form submitting

How to know if a Active Directory user can login interactively

TypeError: fit_transform() missing 1 required positional argument: 'X'