473,785 Members | 2,738 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Should templates be included in pch files?

I thought that including template headers such as <vector> in the pch is not
useful.
Templates can’t be compiled without the template arguments so there is no
way to pre compile them.

Is this true?

Also, it seems that this could actually be bad since it will significantly
increase the size of the pch file which I would think could slow the
compilation processes due to the additional memory overhead.

Am I correct?

Dec 24 '05 #1
3 1534
Scythen wrote:
I thought that including template headers such as <vector> in the pch
is not useful.
Templates can't be compiled without the template arguments so there
is no way to pre compile them.

Is this true?

Also, it seems that this could actually be bad since it will
significantly increase the size of the pch file which I would think
could slow the compilation processes due to the additional memory
overhead.

Am I correct?


You can put anything you want in the headers that are used to build the .pch
file, including templates.

Think of the PCH file as "Pre Parsed Header" instead of "Pre Compiled
Header" and it'll make perfect sense. The PCH file is really nothing more
than a dump of the compiler front-end's heap after parsing all of the text
in the "pre compiled" headers.

-cd
Dec 24 '05 #2
Ok, that makes sense.

But even so, would template files not greatly increase the amount of data in
the PCH. More so than non template code?

I’m trying to figure out what is making a particular project have very long
compile times and also get random "Fatal Error C1055: compiler limit : out of
keys" errors.

I thought I was on to something when I found that the PCH is over 60 Mb in
size but maybe not.
Dec 24 '05 #3
Scythen wrote:
Ok, that makes sense.

But even so, would template files not greatly increase the amount of
data in the PCH. More so than non template code?
Perhaps. Perhaps not. I wouldn't think templates should be any more space
consuming in the front-end than non-template code of the same size and
complexity.

I'm trying to figure out what is making a particular project have
very long compile times and also get random "Fatal Error C1055:
compiler limit : out of keys" errors.
very long compile times are usually due to deep recursion during template
instantiation.

On the C1055 error, MSDN has this to say:

compiler limit : out of keys

The source file contains too many symbols. The compiler ran out of hash keys
for the symbol table.

Possible solutions

Split the source file into smaller files.
Eliminate unnecessary header files.
Reuse temporary and global variables instead of creating new ones
I thought I was on to something when I found that the PCH is over 60
Mb in size but maybe not.


That's large, but not enormous.

-cd
Dec 24 '05 #4

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

1
1440
by: Martman | last post by:
Can someone point me to a good resource explaining how and why to use templates in php. I am new to php and wondering if these so called templates are just include files or what. And I have read several things about libraries in php but some of the applications I see are using includeonce files. Please don't tell me these are the same as libraries. I would consider libraries an application global resource that does not need to be...
7
2382
by: Steven C. | last post by:
When you compile a cpp program that includes a template class in a .h file where does the compiled code go for that templated class? If it went in the obj for the cpp program seems to me you could end up with multiple templates of the same type if the .h file was included in multiple .cpp. Seems more straight forward that it would be put in a obj for the .h and the compiler would just add new ones to the obj for template types that had...
5
4792
by: Christian Christmann | last post by:
Hi, I want to implement an graph using templates. In my header file I define the templates node and edge: template <class NODE> class GNode { NODE *info; public: GraphNode();
0
1161
by: AntonB | last post by:
I am using Visual Studio 2005 Beta1 and get the following errors when building a .NET class library (called TryDLLPr in the example below). Any advice on what's wrong will be greatly appreciated. The errors given are: TryDLLPr.obj : error LNK2022: metadata operation failed (801311D6) : Differing number of methods in duplicated types (TryInclude.AVect<int>): (0x02000005). LINK : fatal error LNK1255: link failed because of metadata errors...
3
1012
by: Lars Netzel | last post by:
In VB6 I remember finding templates for forms like "About " and "Licence Agreemenet" and so on when creating a new Form. Where are they in .NET, not included? Can you download Froms like that, for example an About form.. to get the Design right? /Lars Netzel
4
2005
by: Steven T. Hatton | last post by:
<quote url="http://www.informit.com/guides/content.asp?g=cplusplus&seqNum=53&rl=1"> exported Templates Last updated Sep 6, 2006. exported Templates The separate compilation model enables us to define functions, types and objects in one translation unit and refer to them from other translation
14
2203
by: aaragon | last post by:
Hi everyone, I've been writing some code and so far I have all the code written in the .h files in order to avoid the linker errors. I'm using templates. I wanted to move the implementations to the .cpp files. After some reading, I found that the only way to do this is to add the actual template instantiations in the .cpp file. But, how do you do that if you're not working with built-in types? For example, a template class might be,
4
8000
by: zfareed | last post by:
#include <iostream> #include <fstream> using namespace std; template<class ItemType> class SortedList { private:
2
1521
by: Sunil Varma | last post by:
Hi, I'm trying to write template functions and use them. Is it possible to declare a template function in a .h file and define it in a .cpp file. Ex: //temp_func.h
0
9643
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...
0
9480
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it. First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
0
10319
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...
0
10147
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth. The Art of Business Website Design Your website is...
1
10087
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
0
6737
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
0
5380
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
2
3645
muto222
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.
3
2877
bsmnconsultancy
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.