/ifcMap

This switch tells the compiler where to find the IFC reference map file, which maps references to named modules and header units to their corresponding IFC (.ifc) files.

Syntax

/ifcMap filename

Remarks

The filename argument specifies the IFC reference map file. It can be relative to the compiler's working directory, or an absolute path.

You can provide multiple /ifcMap arguments to the compiler.

The IFC reference map file format is a subset of the TOML file format. The IFC reference map file can contain a mix of [[module]] and [[header-unit]] references.

Syntax errors or unrecognized table names result in compiler error C7696 (TOML parse error).

Map named modules

The format of the IFC reference map file for named modules is:

# Using literal strings
[[module]]
name = 'M'
ifc = 'C:\modules\M.ifc'

# Using basic strings
[[module]]
name = "N"
ifc = "C:\\modules\\N.ifc"

This IFC reference map file maps the named modules 'M' and 'N' to their respective IFC files. The equivalent /reference is:

/reference M=C:\modules\M.ifc /reference N=C:\modules\N.ifc

For more information about what types of module names are valid for the name field, see /reference remarks.

Map header units

The format of the IFC reference map file for header units is:

# Using literal strings
[[header-unit]]
name = ['quote', 'my-utility.h']
ifc = 'C:\header-units\my-utility.h.ifc'

[[header-unit]]
name = ['angle', 'vector']
ifc = 'C:\header-units\vector.ifc'

# Using basic strings
[[header-unit]]
name = ["quote", "my-engine.h"]
ifc = "C:\\header-units\\my-engine.h.ifc"

[[header-unit]]
name = ["angle", "algorithm"]
ifc = "C:\\header-units\\algorithm.ifc"

This IFC reference map file maps "my-utility.h" to C:\header-units\my-utility.h.ifc, and <vector> to C:\header-units\vector.ifc, and so on. The equivalent /headerUnit is:

/headerUnit:quote my-utility=C:\header-units\my-utility.h.ifc /headerUnit:angle vector=C:\header-units\vector.ifc /headerUnit:quote my-engine.h=C:\header-units\my-engine.h.ifc /headerUnit:angle algorithm=C:\header-units\algorithm.ifc

When [[header-unit]] is specified in an IFC reference map file, the compiler implicitly enables /Zc:preprocessor, just as it's implicitly enabled when /headerUnit is used. For more information about the behavior of the angle and quote lookup methods, see /headerUnit remarks.

See also

Overview of modules in C++
Walkthrough: Build and import header units in Visual C++ projects
Using C++ Modules in MSVC from the Command Line