Hi everyone,
For my project, I need to link zlib from Boost library to my project.
I followed this tutorial Linking_Static_Libraries_Using_The_Build_System but I end up to get this error : LNK2019: unresolved external symbol.
I spent almost 2 days to resolve this problem by looking on the AnswerHub and on the Google but without success.
Here is the full Compilation log
The library Boost is in a folder Plugins at the root of the project.
My *.build.cs file looks like that :
using UnrealBuildTool;
using System.IO;
public class TestImport : ModuleRules
{
private string ModulePath
{
get { return Path.GetDirectoryName(RulesCompiler.GetModuleFilename(this.GetType().Name)); }
}
private string ThirdPartyPath
{
get { return Path.GetFullPath(Path.Combine(ModulePath, "../../ThirdParty/")); }
}
private string PluginsPath
{
get { return Path.GetFullPath(Path.Combine(ModulePath, "../../Plugins")); }
}
public TestImport(TargetInfo Target)
{
PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "ImageWrapper" });
PrivateDependencyModuleNames.AddRange(new string[] { "RHI", "RenderCore", "ShaderCore" });
LoadLibs(Target);
}
public bool LoadLibs(TargetInfo Target)
{
bool isLibrarySupported = false;
if ((Target.Platform == UnrealTargetPlatform.Win64) || (Target.Platform == UnrealTargetPlatform.Win32))
{
isLibrarySupported = true;
string PlatformString = (Target.Platform == UnrealTargetPlatform.Win64) ? "x64" : "x86";
string LibrariesPath = Path.Combine(PluginsPath, "Boost", "lib", PlatformString);
PublicLibraryPaths.Add(LibrariesPath);
PublicAdditionalLibraries.Add(Path.Combine(LibrariesPath, "libboost_iostreams-vc120-mt-1_57.lib"));
PublicAdditionalLibraries.Add(Path.Combine(LibrariesPath, "libboost_zlib-vc120-mt-gd-1_57.lib"));
}
if (isLibrarySupported)
{
PublicIncludePaths.Add(Path.Combine(PluginsPath, "Boost", "include"));
}
Definitions.Add(string.Format("WITH_BOOST_BINDING={0}", isLibrarySupported ? 1 : 0));
return isLibrarySupported;
}
}
In a standalone C++ project, it works perfectly with Boost Library and zlib but the integration in UE is quite awfull
If someone has some tips for me, it would be great ! 
Thanks !